Wet wipe dispensing system for dispensing warm wet wipes

ABSTRACT

In a dispensing system and process for dispensing a warm wet wipe, a wet has an aqueous solution and microencapsulated delivery vehicles including a temperature change agent capable of generating a temperature change upon contact with the aqueous solution. An activating device facilitates rupturing of the microencapsulated delivery vehicles as the wet wipe is removed from a wet wipe container to allow contact between the temperature change agent and the aqueous solution of the wet wipe to thereby dispense a warm wet wipe. In another embodiment the wet wipe in the container has an aqueous solution. A lotion having the microencapsulated delivery vehicles is disposed in a lotion container free from contact with the wet wipe. An applicator in communication with the lotion is operable to apply the lotion to the wet wipe while the wet wipe is disposed at least in part within the wet wipe container.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates generally to dispensing systems fordispensing warm wet wipes or wet wipes capable of warming quickly afterbeing dispensed, and processes for dispensing warm wet wipes or wetwipes capable of warming quickly after being dispensing. The warmingsensation on the surface of the wet wipe is caused by the interaction ofa heating agent initially contained in a microencapsulated heat deliveryvehicle with an aqueous solution contained in the wet wipe.

Wet wipes and related products have been used for some time by consumersfor various cleaning and wiping tasks. For example, many parents haveutilized wet wipes to clean the skin of infants and toddlers before andafter urination and/or defecation. Many types of wet wipes are currentlycommercially available for this purpose and are known in the art.

Today, many consumers are demanding that personal health care products,such as wet wipes, have the ability to not only provide their intendedcleaning function, but also to deliver a comfort benefit to the user. Inrecent studies, it has been shown that baby wet wipes currently on themarket are sometimes perceived to be uncomfortably cold upon applicationto the skin, particularly for newborns. To mitigate this problem, therehave been many attempts to produce warming products or warmingdispensers to warm the wet wipes to comfort the wet wipe users from theinherent “chill” given off by the contact of the moistened wipes uponthe skin.

These warming products are generally electrically operated and come intwo distinct styles. One is an “electric blanket” style which is sizedto wrap around the external surfaces of a plastic wet wipes container ordispenser. The other is a self-contained plastic “appliance” style whichwarms the wet wipes with its internally positioned heating element.Though such currently known and available wet wipe warming productstypically achieve their primary objective of warming the wet wipe priorto use, they possess certain deficiencies, which can detract from theiroverall utility and desirability.

Perhaps the biggest deficiency of the current wet wipe warming productsand dispensers is their inability to sustain the moisture content of thewet wipes. More specifically, drying of the wet wipes occurs due toheating of their moisture which accelerates dehydration. As a result,wet wipes may become dried-out and unusable.

Other complaints by wipe warmer users include discoloration of the wetwipes after heating, which appears to be inevitable because of areaction of various chemicals in the wipes upon the application of heat.Wipe warmer users further complain about warmer inconvenience andpotential electrical fire hazards, which can result with the use ofelectrical warming products.

Based on the foregoing, there is a need in the art for wet wipes and wetwipe dispensing systems that can produce a warming sensation just priorto, or at the point of use, without using external heating products. Itwould be desirable also provide dispensing systems that can extend theshelf life of the wet wipe and heating compounds used therewith.

SUMMARY OF THE DISCLOSURE

The present disclosure relates to wet wipe dispensing systems fordispensing warm or cool wet wipes or wet wipes capable of warming orcooling upon use. In one embodiment, a dispensing system for dispensinga warmed or cooled wet wipe generally comprises a container and a wetwipe disposed in the container. The wet wipe comprises an aqueoussolution and microencapsulated delivery vehicles including a temperaturechange agent, wherein the temperature change agent is capable ofproviding a temperature changee on the wipe upon contact with theaqueous solution. The container is configured to permit removal of thewet wipe therefrom. An activating device facilitates rupturing of themicroencapsulated delivery vehicles as the wet wipe is removed from thecontainer. The rupturing of the microencapsulated delivery vehiclesallows for contact between the temperature change agent and the aqueoussolution of the wet wipe to thereby dispense a warm or cool wet wipe.

In another embodiment, a dispensing system for dispensing warm or coolwet wipes generally comprises a wet wipe container having an internalcompartment for containing wet wipes. A wet wipe is disposed in theinternal compartment of the wet wipe container and comprises an aqueoussolution. A lotion container of the dispensing system has an internalcompartment, separate from the internal compartment of the wet wipecontainer, for containing a lotion. A lotion is contained within theinternal compartment of the lotion container free from contact with thewet wipe in the wet wipe container. The lotion comprisesmicroencapsulated delivery vehicles including a temperature change agentcapable of providing a temperature change upon contact with aqueoussolution. An applicator is in communication with the internalcompartment of the lotion container and is operable to apply the lotionto the wet wipe while the wet wipe is disposed at least in part withinthe wet wipe container. An activating device facilitates rupturing ofthe microencapsulated delivery vehicles as the wet wipe is removed fromthe container whereby rupturing of the microencapsulated deliveryvehicles permits contact between the temperature change agent and theaqueous solution of the wet wipe to thereby dispense a warm or cool wetwipe.

In one embodiment of a dispensing system for dispensing wet wipes thatare capable of warming or cooling upon use, the dispensing systemgenerally comprises a wet wipe container having an internal compartmentfor containing wet wipes. A wet wipe is disposed in the internalcompartment of the wet wipe container and comprises an aqueous solution.A lotion container of the dispensing system has an internal compartment,separate from the internal compartment of the wet wipe container, forcontaining a lotion. A lotion is contained within the internalcompartment of the lotion container free from contact with the wet wipein the wet wipe container. The lotion comprises a temperature changeagent capable of providing a temperature change upon contact with theaqueous solution. An applicator is in communication with the internalcompartment of the lotion container and responsive to the removal of thewet wipe from the wet wipe container to apply the lotion to the wet wipeto facilitate a reaction between the temperature change agent and theaqueous solution in the wet wipe for dispensing a wet wipe capable ofproviding a temperature change upon use.

A process for producing a warm or cool wet wipe, according to oneembodiment, generally comprises providing a wet wipe in a container,with the wet wipe comprising an aqueous solution and microencapsulateddelivery vehicles including a temperature change agent. A wet wipe isdrawn out of the container and the microencapsulated delivery vehiclesare ruptured as the wet wipe is drawn from the wet wipe container toallow the temperature change agent to contact the aqueous solution andprovide a temperature change on wet wipe.

Other features of the present disclosure will be in part apparent and inpart pointed out hereinafter.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a cross sectional view of a microencapsulated heatdelivery vehicle of the present disclosure.

FIG. 2 depicts a fluidized bed coating apparatus for use imparting amoisture protective layer to a microencapsulated heat delivery vehicle.

FIG. 3 is a graph illustrating the heat generation rate for five sizeranges of calcium chloride that were tested in accordance with anexperiment described herein.

FIG. 4 is a graph illustrating the heat generation rate for four sizeranges of magnesium chloride that were tested in accordance with anexperiment described herein.

FIG. 5 is a graph illustrating the conductivity of a solution includinga microencapsulated delivery vehicle having a moisture protective layermade in accordance with an experiment described herein.

FIG. 6 is a graph illustrating the ability of various samples ofmicroencapsulated heat delivery vehicles including moisture protectivelayers to generate heat as tested in accordance with an experimentdescribed herein.

FIG. 7 is a graph illustrating the ability of microencapsulated heatdelivery vehicles including various coating levels of moistureprotective layers to generate heat as tested in accordance with anexperiment described herein.

FIG. 8 is a graph illustrating the ability of microencapsulated heatdelivery vehicles including moisture protective layers to generate heatafter being flooded over various intervals of time with a wettingsolution as tested in accordance with an experiment described herein.

FIGS. 9-11 are graphs illustrating the rupture force required to rupturevarious microencapsulated heat delivery vehicles as tested in accordancewith an experiment described herein.

FIGS. 12-14 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

FIGS. 15-17 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

FIGS. 18-24 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

FIG. 25 is perspective of one embodiment of a dispensing system fordispensing warm wet wipes, with a closure of the dispensing system in aclosed position.

FIG. 26 is perspective of the dispensing system of FIG. 25 with theclosure in an open position.

FIG. 27 is a side elevation of the dispensing system of FIG. 25 withportions broken away to reveal internal construction.

FIG. 28 is a side elevation of a second embodiment of a dispensingsystem for dispensing warm wet wipes, with portions broken away toreveal internal construction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure relates to wet wipe dispensing systems fordispensing warm wet wipes or wet wipes capable of warming upon use. Inone embodiment, the dispensing system includes a wet wipe that containsmicroencapsulated heat delivery vehicles that contain a heating agent.When the wet wipe is dispensed from the dispensing system, the systembreaks the microencapsulated heat delivery vehicles to allow contactbetween the heating agent and the aqueous solution of the wet wipe toproduce a warm wet wipe. In another embodiment, the dispensing systemincludes a compartment for a wet wipe having an aqueous solution thereonand a compartment for a lotion comprising microencapsulated heatdelivery vehicles including a heating agent. The dispensing system iscapable of applying a uniform coating of the lotion onto the wet wipeduring the dispensing thereof. This wipe is capable of warming upon use.In another embodiment, the dispensing system includes a compartment fora wet wipe having an aqueous solution thereon and a compartment for alotion comprising a neat heating agent (a heating agent notencapsulated). The dispensing system is capable of applying a uniformcoating of the lotion onto the wet wipe during the dispensing thereof.This wipe is also capable of warming upon use.

In some embodiments described herein, the lotion including themicroencapsulated heat delivery vehicles containing the heating agents(or neat heating agents not microencapsulated) is held in the dispenserseparately from the wet wipe until the wet wipe is dispensed from thesystem. When the lotion including the microencapsulated heat deliveryvehicles is held separately from the wet wipe (and the aqueous wet wipesolution present on the wet wipe) until the wet wipe is dispensed, oneadvantage realized is that there is a significantly reduced chance ofthe heating agent in the microencapsulated heat delivery vehicle losingpotency before the desired time; that is, because the microencapsulatedheat delivery vehicles including the heating agent are held in acontainer separate from the aqueous solution of the wet wipe, theheating agent cannot contact the aqueous solution prior to mixing andlose potency prior use.

As described more fully herein, the microencapsulated heat deliveryvehicles that contain the heating agent may be included directly on orin the wet wipe in accordance with some embodiments, or may be heldseparately from the wet wipe (i.e., in neat form, or contained in alotion) until the wet wipe is being, or has been, dispensed from adispensing system.

The microencapsulated heat delivery vehicles suitable for use incombination with the wet wipes and dispensing systems and processdescribed herein may include a number of components and layers. Turningnow to FIG. 1, there is shown a cross sectional view of a suitablemicroencapsulated heat delivery vehicle 2. The microencapsulated heatdelivery vehicle 2 includes a fugitive layer 4 surrounding a moistureprotective layer 6 that surrounds an encapsulation layer 8.Additionally, microencapsulated heat delivery vehicle 2 includes a corecomposition 10 that includes a matrix material 100 and a heating agent12 surrounded by a hydrophobic wax material 14, and an encapsulatingactivator 16. Each of these layers and components, some of which areoptional, are more thoroughly discussed below.

The microencapsulated heat delivery vehicles as described herein aredesirably of a size such that, when incorporated into or onto a personalcare product such as a wet wipe, they cannot readily be felt on the skinby the user. Generally, the microencapsulated heat delivery vehicleshave a diameter of from about 5 micrometers to about 10,000 micrometers,desirably from about 5 micrometers to about 5000 micrometers, desirablyfrom about 50 micrometers to about 1000 micrometers, and still moredesirably from about 300 micrometers to about 700 micrometers.

The core composition includes all of the components or materials thatare encapsulated as described herein by, for example, a crosslinkedpolymeric system, to form the microencapsulated delivery vehicles. Thecore composition may include, for example, the matrix material (i.e.,mineral oil), the heating agent (i.e., magnesium chloride) (or otheractive agent as described herein), a surfactant, an encapsulatingactivator, and a hydrophobic wax material that surrounds the heating (orother active) agent.

Generally, the core composition is present in the microencapsulated heatdelivery vehicle in an amount of from about 0.1% (by weightmicroencapsulated heat delivery vehicle) to about 99.99% (by weightmicroencapsulated heat delivery vehicle), desirably from about 1% (byweight microencapsulated heat delivery vehicle) to about 95% (by weightmicroencapsulated heat delivery vehicle), more desirably from about 5%(by weight microencapsulated heat delivery vehicle) to about 90% (byweight microencapsulated heat delivery vehicle), more desirably fromabout 10% (by weight microencapsulated heat delivery vehicle) to about80% (by weight microencapsulated heat delivery vehicle), more desirablyfrom about 15% (by weight microencapsulated heat delivery vehicle) toabout 70% (by weight microencapsulated heat delivery vehicle), and evenmore desirably from about 20% (by weight microencapsulated heat deliveryvehicle) to about 40% (by weight microencapsulated heat deliveryvehicle).

The matrix material included in the core composition is used as acarrying or bulking agent for other components of the microencapsulatedheat delivery vehicle, including, for example, the heating agent, thesurfactant, and the encapsulating activator. Although generallypreferred to be a liquid material, the matrix material may also be a lowmelting material that is a solid at room temperature. The matrixmaterial is desirably a material that is emulsifiable in water.Preferred liquid matrix materials include oils commonly used incommercial cosmetic applications that may impart some skin benefit tothe user, such as a moisturizing or lubricating benefit. Generally,these oils are hydrophobic oils.

Specific examples of suitable liquid matrix materials include, forexample, mineral oil, isopropyl myristate, silicones, copolymers such asblock copolymers, waxes, butters, exotic oils, dimethicone, thermoionicgels, plant oils, animal oils, and combinations thereof. One preferredmaterial for use as the matrix material is mineral oil. The matrixmaterial is generally present in the core composition of themicroencapsulated heat delivery vehicle in an amount of from about 1%(by weight core composition) to about 99% (by weight core composition),desirably from about 10% (by weight core composition) to about 95% (byweight core composition), more desirably from about 15% (by weight corecomposition) to about 75% (by weight core composition), more desirablyfrom about 20% (by weight core composition) to about 50% (by weight corecomposition), more desirably from about 25% (by weight core composition)to about 45% (by weight core composition), and even more desirably fromabout 30% (by weight core composition) to about 40% (by weight corecomposition).

The microencapsulated heat delivery vehicles as disclosed herein alsoinclude a heating agent that is contained in the core composition. Theheating agent releases heat when contacted with water (i.e., the aqueoussolution present in/on a wet wipe) and results in a warm feeling on theskin when used in combination with a personal care product such as a wetwipe. Suitable heating agents for use in the microencapsulated heatdelivery vehicles include compounds with an exothermic heat of hydrationand compounds with an exothermic heat of solution. Suitable compoundsfor use as heating agents in the core composition include, for example,calcium chloride, magnesium chloride, zeolites, aluminum chloride,calcium sulfate, magnesium sulfate, sodium carbonate, sodium sulfate,sodium acetate, metals, slaked lime, quick lime, glycols, andcombinations thereof. The heating agents may be in either hydrous oranhydrous forms, although anhydrous forms are generally preferred.Particularly preferred compounds include magnesium chloride and calciumchloride.

The heating agent is generally included in the core composition of themicroencapsulated heat delivery vehicle in an amount of from about 0.1%(by weight core composition) to about 98% (by weight core composition),desirably from about 1% (by weight core composition) to about 80% (byweight core composition), more desirably from about 20% (by weight corecomposition) to about 70% (by weight core composition), more desirablyfrom about 30% (by weight core composition) to about 60% (by weight corecomposition), more desirably from about 35% (by weight core composition)to about 55% (by weight core composition), and even more desirably about55% (by weight core composition).

The heating agent utilized in the microencapsulated heat deliveryvehicle generally has a particle size of from about 0.05 micrometers toabout 4000 micrometers, desirably from about 10 micrometers to about1000 micrometers, desirably from about 10 micrometers to about 500micrometers, and more desirably from about 10 micrometers to about 100micrometers to facilitate substantial and continuous heat release. Inone specific embodiment, a particle size of from about 149 micrometersto about 355 micrometers is preferred. Although many heating agents asdescribed herein are commercially available in a number of particlesizes, it will be recognized by one skilled in the art that any numberof techniques can be used to grind and produce the desired particlesizes.

Along with the heating agent, a surfactant may optionally be included inthe core composition. As used herein, “surfactant” is intended toinclude surfactants, dispersants, gelling agents, polymeric stabilizers,structurants, structured liquids, liquid crystals, rheologicalmodifiers, grinding aids, defoamers, block copolymers, and combinationsthereof. If a surfactant is utilized, it should be substantiallynon-reactive with the heating agent. A surfactant may be added alongwith a heating agent and matrix material to the core composition as agrinding and mixing aid for the heating agent and to reduce the surfacetension of the core composition and allow for better mixing with waterand an increase in heating ability upon use. In one embodiment, the useof a surfactant in the core composition generally allows for higherloading of the heating material (or other active agent as describedherein) within the core composition without unwanted flocculation of theheating material occurring, which can hinder heat release by the heatingagent.

Any one of a number of surfactant types including anionic, cationic,nonionic, zwitterionic, and combinations thereof can be utilized in thecore composition. One skilled in the art will recognize, based on thedisclosure herein, that different heating agents in combination withdifferent matrix materials may benefit from one type of surfactant morethan another; that is, the preferred surfactant for one chemistry may bedifferent than the preferred surfactant for another. Particularlydesirable surfactants will allow the core composition including thematrix material, heating agent, and surfactant mixture to have asuitable viscosity for thorough mixing; that is, the surfactant will notresult in the mixture having an undesirably high viscosity. Generally,low HLB surfactants are desirable; that is, surfactants having an HLB ofless than about 7. Examples of commercially available surfactantssuitable for use in the matrix material include, for example, Antiterra207 (BYK Chemie, Wallingford, Conn.) and BYK-P104 (BYK Chemie).

When included in the core composition of the microencapsulated heatdelivery vehicles, the surfactant is generally present in an amount offrom about 0.01% (by weight core composition) to about 50% (by weightcore composition), desirably from about 0.1% (by weight corecomposition) to about 25% (by weight core composition), more desirablyfrom about 0.1% (by weight core composition) to about 10% (by weightcore composition), more desirably from about 1% (by weight corecomposition) to about 5% (by weight core composition), and still moredesirably about 1% (by weight core composition).

As will be described in more detail below, during the manufacturingprocess for the microencapsulated heat delivery vehicle, the corecomposition including the matrix material and the heating agent isintroduced into an aqueous environment. During contact with this aqueousenvironment, it may be possible for the heating agent present in thecore composition to come into contact with water. This contact canresult in a loss of potency and deactivation of the heating agent andrender the resulting microencapsulated heat delivery vehicle ineffectivefor its intended purpose. As such, in one embodiment of the presentdisclosure, the heating agent included in the core composition issubstantially completely surrounded by a hydrophobic wax material priorto being introduced into the core composition and ultimately into theaqueous environment. As used herein, the term “hydrophobic wax material”means a material suitable to coat and protect the heating agent (orother active agent) from water. This hydrophobic wax material mayprovide the heating agent with temporary water protection during thetimeframe of exposure to the aqueous environment; that is, thehydrophobic wax material may keep water from contacting the heatingagent. Although the hydrophobic wax material provides protection of theheating agent during treatment of the core composition in an aqueousenvironment, in one embodiment it will gradually dissolve away and offof the heating agent within the core composition over time; that is, thehydrophobic wax material dissolves into the bulk of the core compositionover time and off of the heating agent so that the heating agent can bedirectly contacted with water upon activation in a wipe or otherproduct.

In an alternative embodiment, the hydrophobic wax material does notsubstantially dissolve into the core composition and off of the heatingagent but is removed from the heating agent at the time of use throughshearing or disruption of the hydrophobic wax material; that is, thehydrophobic wax material is mechanically broken off of the heating agentto allow the heating agent access to water.

It is generally desirable to have substantially complete coverage of theheating agent with the hydrophobic wax material to ensure that theheating agent is not susceptible to contact with water during theintroduction of the core composition into the aqueous liquid asdescribed herein. When contacted with a substantially continuous layerof hydrophobic wax material, the core composition including the matrixmaterial and the heating agent can be encapsulated in the liquidenvironment without the heating agent losing potency. Generally, thehydrophobic wax material may be applied to the heating agent in fromabout 1 to about 30 layers, desirably in from about 1 to about 10layers.

Generally, the hydrophobic wax material is present on the heating agentin an amount of from about 1% (by weight heating agent) to about 50% (byweight heating agent), desirably from about 1% (by weight heating agent)to about 40% (by weight heating agent), more desirably from about 1% (byweight heating agent) to about 30% (by weight heating agent), and evenmore desirably from about 1% (by weight heating agent) to about 20% (byweight heating agent). At these levels, there is sufficient hydrophobicwax material present on the heating agent to provide the desired levelof protection, yet not too much to keep it from dissolving over timeinto the core composition to allow for water to access the heating agentat the desired time.

Suitable hydrophobic wax materials for coating the heating agent arerelatively low temperature melting wax materials. Although otherhydrophobic low temperature melting materials can be used to coat theheating agent in accordance with the present disclosure, low temperaturemelting hydrophobic wax materials are generally preferred. In oneembodiment, the hydrophobic wax material has a melting temperature ofless than about 140° C., desirably less than about 90° C. to facilitatethe coating of the heating agent as described below.

Suitable hydrophobic wax materials for use in coating the heating agent(or other active agent) include, for example, organic ester and waxycompounds derived from animal, vegetable, and mineral sources includingmodifications of such compounds in addition to synthetically producedmaterials having similar properties. Specific examples that may be usedalone or in combination include glyceryl tristearate, glyceryldistearate, canola wax, hydrogenated cottonseed oil, hydrogenatedsoybean oil, castor wax, rapeseed wax, beeswax, carnauba wax, candelillawax, microwax, polyethylene, polypropylene, epoxies, long chainalcohols, long chain esters, long chain fatty acids such as stearic acidand behenic acid, hydrogenated plant and animal oils such as fish oil,tallow oil, and soy oil, microcrystalline waxes, metal stearates andmetal fatty acids. Specific commercially available hydrophobic waxmaterials include, for example, Dynasan™ 110, 114, 116, and 118(commercially available from DynaScan Technology Inc., Irvine, Calif.),Sterotex™ (commercially available from ABITEC Corp., Janesville, Wis.);Dritex C (commercially available from Dritex International, LTD., Essex,U.K.); Special Fat™ 42, 44, and 168T.

As noted herein, the microencapsulated heat delivery vehicles include anencapsulation layer that substantially completely surrounds the corecomposition that includes the matrix material, heating agent andoptionally the hydrophobic wax material and the surfactant (andoptionally an encapsulating activator as discussed below). Theencapsulation layer allows the core composition including the heatingagent or other active agent to undergo further processing and usewithout a loss of structural integrity; that is, the encapsulation layerprovides structural integrity to the core composition and its contentsto allow for further processing.

Although described in more detail below, and generally in relation to acrosslinked polymeric material, the encapsulation layer may be comprisedof a polymeric material, a crosslinked polymeric material, a metal, aceramic or a combination thereof, that results in a shell material thatmay be formed during manufacturing. Specifically, the encapsulationlayer may be comprised of crosslinked sodium alginate, anionic dispersedlatex emulsions, crosslinked polyacrylic acid, crosslinked polyvinylalcohol, crosslinked polyvinyl acetate, silicates, carbonates, sulfates,phosphates, borates, polyvinyl pyrolidone, PLA/PGA, thermoionic gels,urea formaldehyde, melamine formaldehyde, polymelamine, crosslinkedstarch, nylon, ureas, hydrocolloids, and combinations thereof. Oneparticularly preferred crosslinked polymeric system is crosslinkedsodium alginate.

The encapsulation layer present in the microencapsulated heat deliveryvehicle generally has a thickness of from about 0.1 micrometers to about500 micrometers, desirably from about 1 micrometer to about 100micrometers, more desirably from about 1 micrometer to about 50micrometers, more desirably from about 1 micrometer to about 20micrometers, and even more desirably from about 10 micrometers to about20 micrometers. At these thicknesses, the crosslinked polymeric layerhas a sufficient thickness to provide its intended function. Theencapsulation layer may be one discrete layer, or may be comprised ofmultiple layers added in one or more steps. Suitable methods formeasuring the thickness of the encapsulation layer (once fractured), andthe other optional layers described herein, include Scanning ElectronMicroscopy (SEM) and Optical Microscopy.

Generally, the encapsulation layer will be present in from about 1 layerto about 30 layers, desirably in from about 1 layer to about 20 layers,and more desirably in from about 1 layer to about 10 layers to providefurther protection.

The encapsulation layer is generally present in the microencapsulatedheat delivery vehicle in an amount of from about 0.001% (by weightmicroencapsulated heat delivery vehicle) to about 99.8% (by weightmicroencapsulated heat delivery vehicle), desirably from about 0.1% (byweight microencapsulated heat delivery vehicle) to about 90% (by weightmicroencapsulated heat delivery vehicle), more desirably from about 1%(by weight microencapsulated heat delivery vehicle) to about 75% (byweight microencapsulated heat delivery vehicle), more desirably fromabout 1% (by weight microencapsulated heat delivery vehicle) to about50% (by weight microencapsulated heat delivery vehicle), more desirablyfrom about 1% (by weight microencapsulated heat delivery vehicle) toabout 20% (by weight microencapsulated heat delivery vehicle), and stillmore desirably about 1% (by weight microencapsulated heat deliveryvehicle).

The microencapsulated heat delivery vehicle as described herein mayoptionally comprise a moisture protective layer to produce asubstantially fluid-impervious microencapsulated heat delivery vehicle.As used herein, “fluid” is meant to include both water (and otherfluids) and oxygen (and other gases) such that “fluid-impervious”includes both water-impervious and oxygen-impervious. Although referredto throughout herein as a “moisture protective layer,” one skilled inthe art based on the disclosure herein will recognize that this layermay be both “moisture protective” and “oxygen protective;” that is, thelayer will protect and insulate the core composition and its contentsfrom both water and oxygen.

When present, the moisture protective layer substantially completelysurrounds the crosslinked polymeric encapsulation layer described above.The moisture protective layer may be utilized when it is desirable toimpart additional water (and/or oxygen) repelling characteristics ontothe microencapsulated heat delivery vehicle. For example, if themicroencapsulated heat delivery vehicle is to be used in a wet wipe, itmay be desirable to utilize a moisture protective layer on top of theencapsulating layer such that the active heating agent is shielded fromthe water contained in the wet wipe solution until the end user rupturesthe microencapsulated heat delivery vehicle at the desired time of useto allow water to contact the heating agent (i.e., during or afterdispensing of the wet wipe). In the absence of a moisture protectivelayer, when the microencapsulated heat delivery vehicle is used in a wetwipe, it may be possible that over time the water present in the wetwipe solution can diffuse and gain access through the crosslinkedencapsulated shell described above and gain access to the heating agentcausing it to release its heat prematurely. If the microencapsulatedheat delivery vehicles are held separate from the wet wipe (i.e., in alotion or gel) prior to dispensing, it may not be necessary in someembodiments to include the moisture protective layer.

The moisture protective layer may be present on the microencapsulatedheat delivery vehicle in one layer or in multiple layers. Desirably, themoisture protective layer will be present in from about 1 layer to about30 layers, desirably in from about 1 layer to about 20 layers, and moredesirably in from about 1 layer to about 10 layers to provide furtherprotection. As noted above, the moisture protective layer substantiallycompletely surrounds the encapsulating layer to keep water from reachingthe internal matrix material and ultimately the heating agent. To ensurethe moisture protective layer substantially completely covers theencapsulating layer, multiple layers may be utilized as noted above.Each of the moisture protective layers generally has a thickness of fromabout 1 micrometer to about 200 micrometers, desirably from about 1micrometer to about 100 micrometers, and even more desirably from about1 micrometer to about 50 micrometers.

The moisture protective layer may comprise any number of materialsincluding, for example, polyols in combination with isocynate,styrene-acrylate, vinyl toluene-acrylate, styrene-butadiene,vinyl-acrylate, polyvinyl butyral, polyvinyl acetate, polyethyleneterephthalate, polypropylene, polystyrene, polymethyl methacrylate, polylactic acid, polyvinylidene chloride, polyvinyldichloride, polyethylene,alkyd polyester, carnauba wax, hydrogenated plant oils, hydrogenatedanimal oils, fumed silica, silicon waxes, titanium dioxide, silicondioxide, metals, metal carbonates, metal sulfates, ceramics, metalphosphates, microcrystalline waxes, and combinations thereof.

Generally, the moisture protective layer is present in themicroencapsulated heat delivery vehicle in an amount of from about0.001% (by weight microencapsulated heat delivery vehicle) to about99.8% (by weight microencapsulated heat delivery vehicle), desirablyfrom about 0.1% (by weight microencapsulated heat delivery vehicle) toabout 90% (by weight microencapsulated heat delivery vehicle), moredesirably in an amount of from about 1% (by weight microencapsulatedheat delivery vehicle) to about 75% (by weight microencapsulated heatdelivery vehicle), more desirably in an amount of from about 1% (byweight microencapsulated heat delivery vehicle) to about 50% (by weightmicroencapsulated heat delivery vehicle), and even more desirably in anamount of from about 5% (by weight microencapsulated heat deliveryvehicle) to about 35% (by weight microencapsulated heat deliveryvehicle).

In addition to the moisture protective layer, the microencapsulated heatdelivery vehicle may also optionally include a fugitive layer thatsurrounds the moisture protective layer, if present, or theencapsulating layer if the moisture protective layer is not present. Thefugitive layer can act to stabilize and protect the microencapsulatedheat delivery vehicle from rupturing prematurely due to mechanical load,or can provide other benefits. When present on the microencapsulatedheat delivery vehicle, the fugitive layer can impart strength andwithstand a given mechanical load until a time when the fugitive layeris ruptured by the end user or is decomposed or degraded in apredictable manner in a wet wipe solution, usually during shipmentand/or storage of the product prior to use. Consequently, the fugitivelayer allows the microencapsulated heat delivery vehicle to surviverelatively high mechanical load conditions commonly experienced inshipping and/or manufacturing.

In one embodiment, the fugitive layer substantially completely surroundsthe moisture protective layer (or the encapsulating layer) such thatthere are substantially no access points to the underlying layer.Alternatively, the fugitive layer may be a non-continuous, porous ornon-porous layer surrounding the moisture protective layer (or theencapsulating layer).

The fugitive layer, similar to the moisture protective layer, may bepresent in multiple layers. Specifically, the fugitive layer may bepresent in anywhere from about 1 to about 30 layers, desirably fromabout 1 to about 20 layers, and more desirably from about 1 to about 10layers. Generally, each fugitive layer may have a thickness of fromabout 1 micrometer to about 200 micrometers, desirably from about 1micrometer to about 100 micrometers, and more desirably from about 1micrometer to about 50 micrometers.

The fugitive layer is generally present in the microencapsulated heatdelivery vehicle in an amount of from about 0.001% (by weightmicroencapsulated heat delivery vehicle) to about 99.8% (by weightmicroencapsulated heat delivery vehicle), desirably in an amount of fromabout 0.1% (by weight microencapsulated heat delivery vehicle) to about90% (by weight microencapsulated heat delivery vehicle), more desirablyin an amount of from about 1% (by weight microencapsulated heat deliveryvehicle) to about 80% (by weight microencapsulated heat deliveryvehicle), more desirably in an amount of from about 1% (by weightmicroencapsulated heat delivery vehicle) to about 75% (by weightmicroencapsulated heat delivery vehicle), and even more desirably in anamount of from about 1% (by weight microencapsulated heat deliveryvehicle) to about 50% (by weight microencapsulated heat deliveryvehicle).

The fugitive layer may be comprised of any one of a number of suitablematerials including, for example, polylactic acid, polymers of dextrose,hydrocolloids, alginate, zein, and combinations thereof. Oneparticularly preferred material for use as the fugitive layer is starch.

The microencapsulated heat delivery vehicles as described herein may bemanufactured in any number of ways as discussed below. The first step inthe manufacturing process is generally to coat the desired heat deliveryvehicle (i.e., magnesium chloride) with a hydrophobic wax material asdescribed above prior to incorporating the hydrophobic waxmaterial-coated heating agent into the core composition. As would berecognized by one skilled in the art based on the disclosure herein,this hydrophobic wax material coating of the heating agent step isoptional and can be eliminated if such a coating is not desired and theheating agent is to be incorporated into the core composition withoutany protective coating. In one optional embodiment, if the heating agentis to be used in combination with a lotion and applied to the wet wipe,the heating agent may be coated with the hydrophobic wax material andintroduced neat into the lotion or gel without any microencapsulation.

In one embodiment, the hydrophobic wax material is coated onto theheating agent by blending the heating agent and hydrophobic wax materialtogether at an elevated temperature sufficient to melt the hydrophobicwax material in the presence of the heating agent and the melted waxmaterial and heating agent stirred sufficiently to coat the heatingagent. After the coating of the heating agent is complete, the mixtureis allowed to cool to room temperature to allow the wax to solidify onthe heating agent particles. After the coated heating agent particleshave cooled, they can be ground to the desired size prior toincorporation into the matrix material.

After the grinding of the hydrophobic wax material-coated heating agent,it may be desirable to subject the ground material to a further processto ensure that the hydrophobic wax material coating is substantiallycomplete around the heating agents. Suitable additional processesinclude, for example, spheroidization (high heat fluidization slightlybelow the melt temperature of the hydrophobic wax material) and ballmilling. These additional processes can be used to ensure substantiallycomplete coverage of the heating agent with the hydrophobic waxmaterial.

In preparing the microencapsulated heat delivery vehicle, a corecomposition including the hydrophobic wax material-coated (or uncoated)heating agent, an optional encapsulating activator, and surfactant (ifutilized) are first mixed together with the matrix material. This corecomposition is the resulting “core material” inside of the encapsulatinglayer(s), although it will be recognized by one skilled in the art basedon the disclosure herein that the encapsulating activator, if initiallypresent in the core composition, may be substantially or completely usedup in the crosslinking reaction described herein. As will be furtherrecognized by one skilled in the art, some methods of forming an outerlayer on the core composition (i.e., coacervation) may not require achemical encapsulating activator to be present in the core composition,but may utilize a change in pH, a change in temperature, and/or a changein ionic strength of the liquid solution to initiate the formation ofthe encapsulating layer around the core composition. Additionally, itwill be further recognized by one skilled in the art based on thedisclosure herein that the encapsulating activator, when present, may belocated outside of the core composition; that is, the encapsulatingactivator may be located in the liquid solution for example, although itis generally desirable to have it located within the core composition.

The encapsulating activator, when present in the core composition, actsas a crosslinking agent to crosslink the encapsulating layer discussedherein. Once the core composition is introduced into a liquid solutioncontaining a crosslinkable compound as described below, theencapsulating activator interacts with the crosslinkable compound andcauses it to crosslink on the outer surface of the composition to form acrosslinked shell. Because the encapsulating activator chemically reactswith the crosslinkable compound contained in the liquid solution, theresulting microencapsulated heat delivery vehicle may not contain anyencapsulating activator in its final form; or, it may contain a smallamount of encapsulating activator not consumed in the crosslinkingreaction, which in some cases may then act as an additional heatingagent.

The encapsulating activator may be any activator capable of initiating acrosslinking reaction in the presence of a crosslinkable compound.Suitable encapsulating activators include, for example, polyvalent ionsof calcium, polyvalent ions of copper, polyvalent ions of barium,silanes, aluminum, titanates, chelators, acids, and combinationsthereof. Specifically, the encapsulating activator may be calciumchloride, calcium sulfate, calcium oleate, calcium palmitate, calciumstearate, calcium hypophosphite, calcium gluconate, calcium formate,calcium citrate, calcium phenylsulfonate, and combinations thereof. Apreferred encapsulating activator is calcium chloride.

The encapsulating activator is generally present in the core compositionin an amount of from about 0.1% (by weight core composition) to about25% (by weight core composition), desirably from about 0.1% (by weightcore composition) to about 15% (by weight core composition), and stillmore desirably from about 0.1% (by weight core composition) to about 10%(by weight composition).

One skilled in the art will recognize based on the disclosure hereinthat the encapsulating activator may be the same chemical compound asthe heating agent; that is, the same chemical compound may act as boththe encapsulating activator and the heating agent. For example, in oneembodiment, calcium chloride may be added to the composition as bothheating agent and encapsulating activator. When a single compound is tofunction as both heating agent and encapsulating activator, an increasedamount is utilized in the composition to ensure there is sufficientcompound remaining after the crosslinking reaction to function as theheating agent. Of course, if a single compound, such as calciumchloride, is to function as both heating agent and encapsulatingactivator, a portion of the calcium chloride may be surrounded asdescribed herein by a hydrophobic wax material prior to incorporationinto the composition. This protected portion of the dual functioncompound would not be available in this embodiment to act as anencapsulating activator.

To produce the core composition including the matrix material, heatingagent (which may or may not be surrounded by a hydrophobic waxmaterial), encapsulating activator and surfactant (if any), the desiredamounts of these components may be optionally passed through a millingdevice that serves to thoroughly mix the components together for furtherprocessing. Suitable wet milling operations include, for example, beadmilling and wet ball milling. Additionally, processes known to thoseskilled in the art such as hammer milling and jet milling may be used tofirst prepare the heating agent, and then disperse the treated heatingagent into the matrix material containing the surfactant andencapsulating activator followed by thorough mixing.

Once the core composition is prepared, it is introduced into a liquidsolution, generally held at room temperature, to activate a crosslinkingreaction to form an outer encapsulating shell that protects the corecomposition and its components (core material) and allows for immediateuse or further processing. Although described herein primarily inreference to a “crosslinking reaction,” it will be recognized by oneskilled in the art based on the disclosure herein that the encapsulationlayer can be formed around the core composition not only by acrosslinking reaction, but also by coacervation, coagulation,flocculation, adsorbtion, complex coacervation and self-assembly, all ofwhich are within the scope of the present disclosure. As such, the term“crosslinking reaction” is meant to include these other methods offorming the encapsulation layer around the core composition.

One particular advantage of one embodiment described herein is that thepresence of the encapsulating activator in the core composition allowsfor almost instantaneous crosslinking when the core composition isintroduced into the solution containing the crosslinkable compound; thisreduces the potential for unwanted heating agent deactivation. In oneembodiment, the core composition is added dropwise into the liquidcontaining the crosslinkable compound and the beads that form when thedrops contact the liquid are kept separated during the crosslinkingreaction using a sufficient amount of stirring and mixing. It ispreferred to use sufficient stirring and mixing to keep the beadsseparate during the crosslinking reaction to ensure that they remainseparate, individual beads and do not form larger agglomerated massesthat are susceptible to numerous defects. Generally, the drops added tothe liquid solution can have a diameter of from about 0.05 millimetersto about 10 millimeters, desirably from about 1 millimeter to about 3millimeters, and still more desirably from about 0.5 millimeters toabout 1 millimeter. Alternatively, the core composition may beintroduced or poured into the liquid solution including thecrosslinkable compound and then subjected to shear sufficient to breakthe paste into small beads for crosslinking thereon.

In one embodiment, the liquid solution includes a crosslinkable compoundthat can be crosslinked in the presence of the encapsulating activatorto form the outer encapsulate shell. Optionally, a surfactant asdescribed herein can also be introduced into the liquid solution tofacilitate crosslinking. When the core composition including theencapsulating activator is introduced into the liquid containing thecrosslinkable compound, the encapsulating activator migrates to theinterface between the core composition and the liquid solution andinitiates the crosslinking reaction on the surface of the corecomposition to allow the encapsulation layer to grow outward toward theliquid solution. The thickness of the resulting encapsulation layersurrounding the core composition can be controlled by (1) controllingthe amount of encapsulating activator included in the core composition;(2) controlling the amount of time the core composition including theencapsulating activator is exposed to the liquid solution including thecrosslinkable compound; and/or (3) controlling the amount ofcrosslinkable compound in the liquid solution. Generally, anencapsulating layer of sufficient and desired thickness can be formedaround the core composition by allowing the core composition to dwell inthe liquid solution including the crosslinkable compound for from about10 seconds to about 40 minutes, desirably from about 5 minutes to about30 minutes, and still more desirably from about 10 minutes to about 20minutes.

It is generally desirable that the liquid solution containing thecrosslinkable compound has a viscosity suitable for allowing sufficientmixing of the formed beads therein; that is, the viscosity of the liquidsolution should not be so high that stirring and mixing is substantiallyimpaired and the ability to keep the formed beads separated reduced. Tothat end, the liquid solution containing the crosslinkable compoundgenerally contains from about 0.1% (by weight liquid solution) to about50% (by weight liquid solution), desirably from about 0.1% (by weightliquid solution) to about 25% (by weight liquid solution) and moredesirably from about 0.1% (by weight liquid solution) to about 1% (byweight liquid solution) crosslinkable compound.

Any number of crosslinkable compounds can be incorporated into theliquid solution to form the encapsulated layer around the corecomposition upon contact with the encapsulating activator. Some suitablecrosslinkable compounds include, for example, sodium alginate, anionicdispersed latex emulsions, polyacrylic acid, polyvinyl alcohol,polyvinyl acetate, silicates, carbonates, sulfates, phosphates, borates,and combinations thereof. A particularly desirable crosslinkablecompound is sodium alginate.

Once a sufficient amount of time has passed for the encapsulating layerto form on the core composition, the formed beads may be removed fromthe liquid including the crosslinkable compound. The resultingmicroencapsulated heat delivery vehicles may optionally be washedseveral times to remove any crosslinkable compound thereon and dried andare then ready for use or for further processing. One suitable washingliquid is deionized water.

In one embodiment, the microencapsulated heat delivery vehicles formedas described above are subjected to a process to impart a moistureprotective layer thereon that surrounds the encapsulated layer thatcomprises the crosslinked compound. This moisture protective layerprovides the microencapsulated heat delivery vehicle with increasedprotection from water; that is, it makes the microencapsulated heatdelivery vehicle substantially fluid impervious and allows themicroencapsulated heat delivery vehicle to survive long term in anaqueous environment and not degrade until the moisture protective layeris ruptured by mechanical action. The moisture protective layer may be asingle layer applied onto the microencapsulated heat delivery vehicle,or may comprise several layers one on top of the other.

The moisture protective layer may be applied to the microencapsulatedheat delivery vehicle utilizing any number of suitable processesincluding, for example, atomizing or dripping a moisture protectivematerial onto the microencapsulated heat delivery vehicle. Additionally,a Wurster coating process may be utilized. When a solution is used toprovide the moisture protective coating, the solids content of thesolution is generally from about 0.1% (by weight solution) to about 70%(by weight solution), desirably from about 0.1% (by weight solution) toabout 60% (by weight solution), and still more desirably from about 5%(by weight solution) to about 40% (by weight solution). Generally, theviscosity of the solution (at 25° C.) including the moisture protectivematerial is from about 0.6 centipoise to about 10,000 centipoise,desirably from about 20 centipoise to about 400 centipoise, and stillmore desirably from about 20 centipoise to about 100 centipoise.

In one specific embodiment, a fluidized bed process is utilized toimpart the moisture protective layer on the microencapsulated heatdelivery vehicle. The fluidized bed is a bed or layer ofmicroencapsulated heat delivery vehicles through which a stream ofheated or unheated carrier gas is passed at a rate sufficient to set themicroencapsulated heat delivery vehicles in motion and cause them to actlike a fluid. As the vehicles are fluidized, a spray of a solutioncomprising a carrier solvent and the moisture protective material isinjected into the bed and contacts the vehicles imparting the moistureprotective material thereon. The treated vehicles are collected when thedesired moisture protective layer thickness is achieved. Themicroencapsulated heat delivery vehicles can be subjected to one or morefluidized bed processes to impart the desired level of moistureprotective layer. A suitable fluidized bed coating apparatus isillustrated in FIG. 2 wherein the fluidized bed reactor 18 includesheated carrier gas supply 20, solvent and moisture protective materialsupply 22, and microencapsulated heat delivery vehicles 24 contained inchamber 26. The heated gas and solvent exit the chamber 26 at the top 28of chamber 26.

In another embodiment, the microencapsulated heat delivery vehicle,which may or may not include a moisture protective layer as describedabove, is subjected to a process for imparting a fugitive layer thereonsurrounding the outermost layer. For example, if the microencapsulatedheat delivery vehicle includes a moisture protective layer, the fugitivelayer would be applied on the microencapsulated heat delivery vehiclesuch that it substantially completely covered the moisture protectivelayer. The fugitive layer can be applied in a single layer, or may beapplied in multiple layers.

The fugitive layer may be applied to the microencapsulated heat delivervehicle utilizing any number of suitable processes including, forexample, atomizing or dripping a fugitive material onto themicroencapsulated heat delivery vehicle. When a solution is used toprovide the fugitive coating, the solids content of the solution isgenerally from about 1% (by weight solution) to about 70% (by weightsolution), desirably from about 10% (by weight solution) to about 60%(by weight solution). The pH of the solution is generally from about 2.5to about 11. Generally, the viscosity of the solution (at 25° C.)including the fugitive material is from about 0.6 centipoise to about10,000 centipoise, desirably from about 20 centipoise to about 400centipoise, and still more desirably from about 20 centipoise to about100 centipoise. Similar to the moisture protective layer, a preferredmethod of applying the fugitive layer utilized a fluidized bed reactor.Also, a Wurster coating process may also be used.

In an alternative embodiment of the present disclosure, the heatingagent in the core composition can be combined with one or more otheractive ingredients to impart additional benefits to the end user; thatis, the core composition may comprise two or more active agents. The twoor more active agents may include a heating agent, or may not include aheating agent. Also, the core composition may include a single activeagent that is not a heating agent. Additionally, the active agent orcombination of active agents can be located in one or more of the layerssurrounding the core composition including, for example, in theencapsulation layer, the moisture protective layer, and/or the fugitivelayer. Also, the active agent or combination of active agents can belocated in-between two of the layers on the microencapsulated deliveryvehicle. For example, in one embodiment the microencapsulated deliveryvehicle may include a heating agent in the core composition surroundedby a crosslinked encapsulation layer surrounded by a moisture protectivelayer that includes therein a fragrance oil.

A number of alternative or additional active agents are suitable forinclusion in the core composition. Active agents such as neurosensoryagents (agents that induce a perception of temperature change withoutinvolving an actual change in temperature such as, for examplepeppermint oil, eucalyptol, eucalyptus oil, methyl salicylate, camphor,tea tree oil, ketals, carboxamides, cyclohexanol derivatives, cyclohexylderivatives, and combinations thereof), cleansing agents (e.g., toothhealth agents, enzymes), appearance modifying agents (e.g., toothwhitening agents, exfoliation agents, skin-firming agents, anti-callousagents, anti-acne agents, anti-aging agents, anti-wrinkle agents,anti-dandruff agents, antiperspirant agents, wound care agents, enzymeagents, scar repair agents, colorant agents, humectant agents, hair careagents such as conditioners, styling agents, and detangling agents),powders, skin coloration agents such as tanning agents, lighteningagents, and brightening agents, shine control agents and drugs),nutrients (e.g., anti-oxidants, transdermal drug delivery agents,botanical extracts, vitamins, magnets, magnetic metals, foods, anddrugs), pesticides (e.g., tooth health ingredients, anti-bacterials,anti-virals, anti-fungals, preservatives, insect repellents, anti-acneagents, anti-dandruff agents, anti-parasite agents, wound care agents,and drugs), surface conditioning agents (e.g., pH adjusting agents,moisturizers, skin conditioners, exfoliation agents, shaving lubricants,skin-firming agents, anti-callous agents, anti-acne agents, anti-agingagents, anti-wrinkle agents, anti-dandruff agents, wound care agents,skin lipids, enzymes, scar care agents, humectants, powders, botanicalextracts, and drugs), hair care agents (e.g., shaving lubricants, hairgrowth inhibitors, hair growth promoters, hair removers, anti-dandruffagents, colorant agents, humectants, hair care agents such asconditioners, styling agents, detangling agents, and drugs),anti-inflammatory agents (e.g., tooth health ingredients, skinconditioners, external analgesic agents, anti-irritant agents,anti-allergy agents, anti-inflammatory agents, wound care agents,transdermal drug delivery, and drugs), emotional benefit agents (e.g.,gas generating agents, fragrances, odor neutralizing materials,exfoliation agents, skin-firming agents, anti-callous agents, anti-acneagents, anti-aging agents, soothing agents, calming agents, externalanalgesic agents, anti-wrinkle agents, anti-dandruff agents,antiperspirants, deodorants, wound care agents, scar care agents,coloring agents, powders, botanical extracts and drugs), indicators(e.g., soil indicators), and organisms.

Additional suitable active agents include abrasive materials, abrasiveslurries, acids, adhesives, alcohols, aldehydes, animal feed additives,antioxidants, appetite suppressants, bases, biocides, blowing agents,botanical extracts, candy, carbohydrates, carbon black, carbonlesscopying materials, catalysts, ceramic slurries, chalcogenides,colorants, cooling agents, corrosion inhibitors, curing agents,detergents, dispersants, EDTA, enzymes, exfoliation, fats, fertilizers,fibers, fire retardant materials, flavors, foams, food additives,fragrances, fuels, fumigants, gas forming compounds, gelatin, graphite,growth regulators, gums, herbicides, herbs, spices, hormonal basedcompounds, humectants, hydrides, hydrogels, imaging materials,ingredients that are easily oxidized or not UV stable, inks, inorganicoxides, inorganic salts, insecticides, ion exchange resins, latexes,leavening agents, liquid crystals, lotions, lubricants, maltodextrins,medicines, metals, mineral supplements, monomers, nanoparticles,nematicides, nicotine-based compounds, oil recovery agents, organicsolvents, paint, peptides, pesticides, pet food additives, phase changematerials, phase change oils, pheromones, phosphates, pigments, dyes,plasticizers, polymers, propellants, proteins, recording materials,silicates, silicone oils, stabilizers, starches, steroids, sugars,surfactants, suspensions, dispersions, emulsions, vitamins, warmingmaterials, waste treatment materials, adsorbents, water insoluble salts,water soluble salts, water treatment materials, waxes, and yeasts.

As noted herein, one or more of these additional active ingredients canbe used in addition to the heating agent in the microencapsulateddelivery vehicle; that is, the active ingredient can be an activeingredient other than a heating agent. For example, one particularactive agent that can be used in addition to the heating agent as theactive material in the microencapsulated delivery vehicle is a coolingagent. In many situations it may be beneficial to provide a product thatis capable of providing a cooling sensation on the skin to soothe andrelieve skin irritation, or to relax muscles. Some situations that mayrequire a cooling sensation on the skin include, for example, soremuscles, sunburned skin, skin over-heated from exercise, hemorrhoids,minor scrapes and burns, and the like. Specific products that mayinclude a cooling agent include, for example, spa gloves and socks, footcreams and wraps, cooling moist bath tissue, topical analgesics, coolinglotions, cooling acne cloths, sunburn relief gels and creams, coolingsuntan lotions, cooling insect bite relief sprays and/or lotions,cooling diaper rash creams, cooling anti-irritation/anti-inflammatorycreams, and cooling eye patches.

Suitable cooling agents are chemical compounds that have a negative heatof solution; that is, suitable cooling agents are chemical compoundsthat when dissolved in water feel cool due to an endothermic chemicalreaction. Some suitable cooling agents for inclusion in themicroencapsulated heat delivery vehicle include, for example, ammoniumnitrate, sodium chloride, potassium chloride, xylitol, barium hydroxide(Ba(OH)₂.8H₂O), barium oxide (BaO.9H₂O), magnesium potassium sulfate(MgSO₄.K₂SO₄.6H₂O), potassium aluminum sulfate (KAl(SO₄)₂.12H₂O), sodiumborate (tetra) (Na₂B₄O₇.10H₂O), sodium phosphate (Na₂HPO₄.12H₂O),sorbitol, urea, and combinations thereof. Similar to the heating agentsdescribed herein, in some embodiments, the cooling agent may besurrounded by a hydrophobic wax material prior to being incorporatedinto the matrix material.

As noted above, the microencapsulated heat delivery vehicles asdescribed herein are suitable for use in a number of products, includingwipe products, wraps, such as medical wraps and bandages, headbands,wristbands, helmet pads, personal care products, cleansers, lotions,emulsions, oils, ointments, salves, balms, and the like. Althoughdescribed primarily herein in relation the wipes, it will be recognizedby one skilled in the art that the microencapsulated delivery vehiclesdescribed herein could be incorporated into any one or more of the otherp4roducts listed above.

Generally, the wipes for use in the dispensing systems and processdescribed herein that include the microencapsulated heat deliveryvehicles can be wet wipes. As used herein, the term “wet wipe” means awipe that includes greater than about 70% (by weight substrate) moisturecontent. Specifically, suitable wipes for use in the present disclosurecan include wet wipes, hand wipes, face wipes, cosmetic wipes, householdwipes, industrial wipes, and the like. Particularly preferred wipes arewet wipes, and other wipe-types that include a solution, such as babywet wipes.

Materials suitable for the substrate of the wipes are well know to thoseskilled in the art, and are typically made from a fibrous sheet materialwhich may be either woven or nonwoven. For example, suitable materialsfor use in the wipes may include nonwoven fibrous sheet materials whichinclude meltblown, coform, air-laid, bonded-carded web materials,hydroentangled materials, and combinations thereof. Such materials canbe comprised of synthetic or natural fibers, or a combination thereof.Typically, the wipes of the present disclosure define a basis weight offrom about 25 grams per square meter to about 120 grams per square meterand desirably from about 40 grams per square meter to about 90 grams persquare meter.

In one particular embodiment, the wipes of the present disclosurecomprise a coform basesheet of polymer fibers and absorbent fibershaving a basis weight of from about 60 to about 80 grams per squaremeter and desirably about 75 grams per square meter. Such coformbasesheets are manufactured generally as described in U.S. Pat. No.4,100,324, issued to Anderson, et al. (Jul. 11, 1978); U.S. Pat. No.5,284,703, issued to Everhart, et al. (Feb. 8, 1994); and U.S. Pat. No.5,350,624, issued to Georger, et al. (Sep. 27, 1994), which areincorporated by reference to the extent to which they are consistentherewith. Typically, such coform basesheets comprise a gas-formed matrixof thermoplastic polymeric meltblown fibers and cellulosic fibers.Various suitable materials may be used to provide the polymericmeltblown fibers, such as, for example, polypropylene microfibers.Alternatively, the polymeric meltblown fibers may be elastomeric polymerfibers, such as those provided by a polymer resin. For instance,Vistamaxx® elastic olefin copolymer resin designated PLTD-1810,available from ExxonMobil Corporation (Houston, Tex.) or KRATON G-2755,available from Kraton Polymers (Houston, Tex.) may be used to providestretchable polymeric meltblown fibers for the coform basesheets. Othersuitable polymeric materials or combinations thereof may alternativelybe utilized as known in the art.

As noted above, the coform basesheet additionally may comprise variousabsorbent cellulosic fibers, such as, for example, wood pulp fibers.Suitable commercially available cellulosic fibers for use in the coformbasesheets can include, for example, NF 405, which is a chemicallytreated bleached southern softwood Kraft pulp, available fromWeyerhaeuser Co. of Federal Way (Washington); NB 416, which is ableached southern softwood Kraft pulp, available from Weyerhaeuser Co.;CR-0056, which is a fully debonded softwood pulp, available fromBowater, Inc. (Greenville, S.C.); Golden Isles 4822 debonded softwoodpulp, available from Koch Cellulose (Brunswick, Ga.); and SULPHATATE HJ,which is a chemically modified hardwood pulp, available from Rayonier,Inc. (Jesup, Ga.).

The relative percentages of the polymeric meltblown fibers andcellulosic fibers in the coform basesheet can vary over a wide rangedepending upon the desired characteristics of the wipes. For example,the coform basesheet may comprise from about 10 weight percent to about90 weight percent, desirably from about 20 weight percent to about 60weight percent, and more desirably from about 25 weight percent to about35 weight percent of the polymeric meltblown fibers based on the dryweight of the coform basesheet being used to provide the wipes.

In an alternative embodiment, the wipes of the present disclosure cancomprise a composite which includes multiple layers of materials. Forexample, the wipes may include a three layer composite which includes anelastomeric film or meltblown layer between two coform layers asdescribed above. In such a configuration, the coform layers may define abasis weight of from about 15 grams per square meter to about 30 gramsper square meter and the elastomeric layer may include a film materialsuch as a polyethylene metallocene film. Such composites aremanufactured generally as described in U.S. Pat. No. 6,946,413, issuedto Lange, et al. (Sep. 20, 2005), which is hereby incorporated byreference to the extent it is consistent herewith.

In accordance with the present disclosure, the contents (i.e., heatingagent) of the microencapsulated heat delivery vehicle as describedherein are capable of generating heat to produce a warming sensation inthe wipe upon being activated (i.e., ruptured) and wetted. In oneembodiment, the wipe is a wet wipe comprising a wetting solution inaddition to the fibrous sheet material and the microencapsulated heatdelivery vehicle. When the microencapsulated heat delivery vehicle isruptured, its contents contact the wetting solution (i.e., aqueoussolution) of the wet wipe, and an exothermic reaction occurs, therebywarming the wipe. The wetting solution can be any wetting solution knownto one skilled in the wet wipe art. Generally, the wetting solution caninclude water, emollients, surfactants, preservatives, chelating agents,pH adjusting agents, skin conditioners, fragrances, and combinationsthereof. For example, one suitable wetting solution for use in the wetwipe of the present disclosure comprises about 98% (by weight) water,about 0.6% (by weight) surfactant, about 0.3% (by weight) humectant,about 0.3% (by weight) emulsifier, about 0.2% (by weight) chelatingagent, about 0.35% (by weight) preservative, about 0.002% (by weight)skin conditioning agent, about 0.03% (by weight) fragrance, and about0.07% (by weight) pH adjusting agent. One specific wetting solutionsuitable for use in the wet wipe of the present disclosure is describedin U.S. Pat. No. 6,673,358, issued to Cole et al. (Jan. 6, 2004), whichis incorporated herein by reference to the extent it is consistentherewith.

It has been determined that the ideal temperature for a wipe to beutilized is a temperature of from about 30° C. to about 40° C. (86°F.-104° F.). A conventional wipe will typically be stored at roomtemperature (about 23° C. (73.4° F.). As such, when themicroencapsulated heat delivery vehicle ruptures, and releases itscontents, and the contents contact an aqueous solution, a warmingsensation is produced, increasing the temperature of the solution andwipe by at least about 5° C. More suitably, the temperature of thesolution and wipe is increased by at least about 10° C., even moresuitably, increased by at least about 15° C., and even more suitablyincreased by at least about 20° C. or more.

Generally, the elapsed time between the dispensing of a wipe product anduse of the product is about 2 seconds or less, and typically is about 6seconds or less. As such, once the microencapsulated heat deliveryvehicle of the present disclosure is ruptured and its contents contactedby water, the contents of the microencapsulated heat delivery vehiclebegin to generate heat and a warming sensation is suitably perceived inless than about 20 seconds. More suitably, the warming sensation isperceived in less than about 10 seconds, even more suitably, in lessthan about 5 seconds, and even more suitably, in less than about 2seconds.

Additionally, once the warming sensation begins, the warming sensationof the wipe product is suitably maintained for at least about 5 seconds.More suitably, the warming sensation is maintained for at least about 8seconds, even more suitably for at least about 15 seconds, even moresuitably for at least about 20 seconds, even more suitably for at leastabout 40 seconds, and even more suitably for at least about 1 minute.

To generate the temperature increase described above, the wipes of thepresent disclosure suitably comprise from about 0.33 grams per squaremeter to about 500 grams per square meter microencapsulated heatdelivery vehicle. More suitably, the wipes comprise from about 6.0 gramsper square meter to about 175 grams per square meter microencapsulatedheat delivery vehicle, even more suitably from about 16 grams per squaremeter to about 90 grams per square meter, and even more suitably, fromabout 30 grams per square meter to about 75 grams per square metermicroencapsulated heat delivery vehicle.

The microencapsulated heat delivery vehicle can be applied to the wipeusing any means known to one skilled in the art. Preferably, themicroencapsulated heat delivery vehicle is embedded into the core of thefibrous sheet material of the wipe. By embedding the microencapsulatedheat delivery vehicle into the core of the fibrous sheet material, thewipe will have a reduced grittiness feel because of a cushion effect andthe ruptured shells of the microencapsulated heat delivery vehicle willnot come into direct contact with the user's skin. Additionally, whenthe microencapsulated heat delivery vehicle is located in the core ofthe fibrous sheet material, the microencapsulated heat delivery vehicleis better protected from premature heat release caused by the conditionsof manufacturing, storage, and transportation of the wipe.

In one embodiment, the microencapsulated heat delivery vehicle isembedded inside of the fibrous sheet material. For example, in onespecific embodiment, the fibrous sheet material is one or more meltblownlayers made by providing a stream of extruded molten polymeric fibers.To incorporate the microencapsulated heat delivery vehicles, a stream ofmicroencapsulated heat delivery vehicles can be merged with the streamof extruded molten polymeric fibers and collected on a forming surfacesuch as a forming belt or forming drum to form the wipe comprising themicroencapsulated heat delivery vehicle. Optionally, a forming layer canbe placed on the forming surface and used to collect themicroencapsulated heat delivery vehicles in the wipe. By using thismethod, the microencapsulated heat delivery vehicle is mechanicallyentrapped within the forming layer.

The stream of meltblown polymeric fibers may be provided by meltblowinga copolymer resin or other polymer. For example, in one embodiment, themelt temperature for a copolymer resin such as Vistamaxx® PLTD 1810 canbe from about 450° F. (232° C.) to about 540° F. (282° C.). As notedabove, suitable techniques for producing nonwoven fibrous webs, whichinclude meltblown fibers, are described in the previously incorporatedU.S. Pat. Nos. 4,100,324 and 5,350,624. The meltblowing techniques canbe readily adjusted in accordance with the knowledge of one skilled inthe art to provide turbulent flows that can operatively intermix thefibers and the microencapsulated heat delivery vehicles. For example,the primary air pressure may be set at 5 pounds per square inch (psi)and the meltblown nozzles may be 0.020 inch spinneret hole nozzles.

Additionally, immediately following the formation of the meltblownstructure, the meltblown polymeric fibers can be tacky, which can beadjusted to provide additional adhesiveness between the fibers and themicroencapsulated heat delivery vehicles.

In another embodiment, the fibrous sheet material is a coform basesheetcomprising a matrix of thermoplastic polymeric meltblown fibers andabsorbent cellulosic fibers. Similar to the meltblown embodiment above,when the fibrous sheet material is a matrix of thermoplastic polymericmeltblown fibers and absorbent cellulosic fibers, a stream ofmicroencapsulated heat delivery vehicles can be merged with a stream ofcellulosic fibers and a stream of polymeric fibers into a single streamand collected on a forming surface such as a forming belt or formingdrum to form a wipe comprising a fibrous sheet material with themicroencapsulated heat delivery vehicles within its core.

The stream of absorbent cellulosic fibers may be provided by feeding apulp sheet into a fiberizer, hammermill, or similar device as is knownin the art. Suitable fiberizers are available from Hollingsworth(Greenville, S.C.) and are described in U.S. Pat. No. 4,375,448, issuedto Appel, et al. (Mar. 1, 1983), which is incorporated by reference tothe extent to which it is consistent herewith. The stream of polymericfibers can be provided as described above.

The thickness of the fibrous sheet material will typically depend uponthe diameter size of the microencapsulated heat delivery vehicle, thefibrous sheet material basis weight, and the microencapsulated heatdelivery vehicle loading. For example, as the size of themicroencapsulated heat delivery vehicle is increased, the fibrous sheetmaterial must be thicker to prevent the wipe from having a gritty feel.

In another embodiment, the fibrous sheet material is made up of morethan one layer. For example, when the fibrous sheet material is ameltblown material, the fibrous sheet material can suitably be made upof two meltblown layers secured together, more suitably three meltblownlayers, even more suitably four meltblown layers, and even more suitablyfive or more meltblown layers. When the fibrous sheet material is acoform basesheet, the fibrous sheet material can suitably be made up oftwo coform basesheet layers secured together, more suitably three coformbasesheet layers, even more suitably four coform basesheet layers, evenmore suitably five or more coform basesheet layers. Moreover, when thefibrous sheet material includes a film, the fibrous sheet material cansuitably be made up of two film layers, more suitably three film layers,even more suitably four film layers, and even more suitably five or morefilm layers. In one embodiment, the layers are separate layers. Inanother embodiment, the layers are plied together.

Using the additional layers will allow for improved capture of themicroencapsulated heat delivery vehicle. This helps to ensure themicroencapsulated heat delivery vehicle will remain in the wipe duringshipping and storage. Additionally, as the microencapsulated heatdelivery vehicle becomes further entrapped in the fibrous sheetmaterial, the grittiness of the wipe is reduced.

To incorporate the microencapsulated heat delivery vehicle in betweenthe layers of fibrous sheet material, the microencapsulated heatdelivery vehicle is sandwiched between a first layer and a second layerof the fibrous sheet material, and the layers are then laminatedtogether using any means known in the art. For example, the layers canbe secured together thermally or by a suitable laminating adhesivecomposition.

Thermal bonding includes continuous or discontinuous bonding using aheated roll. Point bonding is one suitable example of such a technique.Thermal bonds should also be understood to include various ultrasonic,microwave, and other bonding methods wherein the heat is generated inthe non-woven or the film.

In a preferred embodiment, the first layer and second layer arelaminated together using a water insoluble adhesive composition.Suitable water insoluble adhesive compositions can include hot meltadhesives and latex adhesives as described in U.S. Pat. No. 6,550,633,issued to Huang, et al. (Apr. 22, 2003); U.S. Pat. No. 6,838,154, issuedto Anderson, et al. (Oct. 25, 2005); and U.S. Pat. No. 6,958,103, issuedto Varona et al. (Jan. 4, 2005), which are hereby incorporated byreference to the extent they are consistent herewith. Suitable hot meltadhesives can include, for example, RT 2730 APAO and RT 2715 APAO, whichare amorphous polyalphaolefin adhesives (commercially available fromHuntsman Polymers Corporation, Odessa, Tex.) and H2800, H2727A, andH2525A, which are all styrenic block copolymers (commercially availablefrom Bostik Findley, Inc., Wauwatosa, Wis.). Suitable latex adhesivesinclude, for example, DUR-O-SET E-200 (commercially available fromNational Starch and Chemical Co., Ltd., Bridgewater, N.J.) and Hycar26684 (commercially available from B.F. Goodrich, Laval, Quebec).

The water insoluble adhesive composition can additionally be used incombination with the microencapsulated heat delivery vehicle between thefirst and second layers of the fibrous sheet material. The waterinsoluble adhesive composition will provide improved binding of themicroencapsulated heat delivery vehicle to the first and second layersof the fibrous sheet material. Typically, the adhesive composition canbe applied to the desired area by spraying, knifing, roller coating, orany other means suitable in the art for applying adhesive compositions.

Suitably, the adhesive composition can be applied to the desired area ofthe wipe in an amount of from about 0.01 grams per square meter to about20 grams per square meter. More suitably, the adhesive composition canbe applied in an amount of from about 0.05 grams per square meter toabout 0.5 grams per square meter.

In yet another embodiment, the microencapsulated heat delivery vehiclemay be distributed within a pocket of the fibrous sheet material.Similar to the pattern distribution method described herein below, thepockets of microencapsulated heat delivery vehicles provide for atargeted warming sensation in the wipe.

As an alternative to embedding the microencapsulated heat deliveryvehicles into the core of the fibrous sheet material, themicroencapsulated heat delivery vehicles can be deposited on the outersurface of the fibrous sheet material. In one embodiment, themicroencapsulated heat delivery vehicles are deposited on one outersurface of the fibrous sheet material. In another embodiment, themicroencapsulated heat delivery vehicles are deposited on both outersurfaces of the fibrous sheet material.

To provide for better attachment of the microencapsulated heat deliveryvehicles to the outer surface of the fibrous sheet material, a waterinsoluble adhesive composition can be applied with the microencapsulatedheat delivery vehicles onto the outer surface of the fibrous sheetmaterial. Suitable water insoluble adhesive compositions are describedherein above. Suitably, the adhesive composition can be applied to theouter surface of the fibrous sheet material in an amount of from about0.01 grams per square meter to about 20 grams per square meter. Moresuitably, the adhesive composition can be applied in an amount of fromabout 0.05 grams per square meter to about 0.5 grams per square meter.

The microencapsulated heat delivery vehicles may be embedded in ordistributed on the fibrous sheet material in a continuous layer or apatterned layer. By using a patterned layer, a targeted warmingsensation can be achieved. These methods of distribution canadditionally reduce manufacturing costs as reduced amounts ofmicroencapsulated heat delivery vehicles are required. Suitably, themicroencapsulated heat delivery vehicles can be distributed in patternsincluding, for example, characters, an array of separate lines, swirls,numbers, or dots of microencapsulated heat delivery vehicles. Continuouspatterns, such as stripes or separate lines that run parallel with themachine direction of the web, are particularly preferred as thesepatterns may be more process-friendly.

Additionally, the microencapsulated heat delivery vehicles may becolored using a coloring agent prior to applying the microencapsulatedheat delivery vehicles to the fibrous sheet material. The coloring ofthe microencapsulated heat delivery vehicles can improve the aestheticsof the wipe. Additionally, in embodiments where targeted warming isdesired, the coloring of the microencapsulated heat delivery vehiclescan direct the consumer of the wipe product to the location of themicroencapsulated heat delivery vehicles in the wipe.

Suitable coloring agents include, for example, dyes, color additives,and pigments or lakes. Suitable dyes include, for example, Blue 1, Blue4, Brown 1, External Violet 2, External Violet 7, Green 3, Green 5,Green 8, Orange 4, Orange 5, Orange 10, Orange 11, Red 4, Red 6, Red 7,Red 17, Red 21, Red 22, Red 27, Red 28, Red 30, Red 31, Red 33, Red 34,Red 36, Red 40, Violet 2, Yellow 5, Yellow 6, Yellow 7, Yellow 8, Yellow10, Yellow 11, Acid Red 195, Anthocyanins, Beetroot Red, BromocresolGreen, Bromothymol Blue, Capsanthin/Capsorubin, Curcumin, andLactoflavin. Also, many dyes found suitable for use in the EuropeanUnion and in Japan may be suitable for use as coloring agents in thepresent disclosure.

Suitable color additives include, for example, aluminum powder, annatto,bismuth citrate, bismuth oxychloride, bronze powder, caramel, carmine,beta carotene, chloraphyllin-copper complex, chromium hydroxide green,chromium oxide greens, copper powder, disodium EDTA-copper, ferricammonium ferrocyanide, ferric ferrocyanide, guauazulene, guanine, henna,iron oxides, lead acetate, manganese violet, mica, pyrophylite, silver,titanium dioxide, ultramarines, zinc oxide, and combinations thereof.

Suitable pigments or lakes include, for example, Blue 1 Lake, ExternalYellow 7 Lake, Green 3 Lake, Orange 4 Lake, Orange 5 Lake, Orange 10Lake, Red 4 Lake, Red 6 Lake, Red 7 Lake, Red 21 Lake, Red 22 Lake, Red27 Lake, Red 28 Lake, Red 30 Lake, Red 31 Lake, Red 33 Lake, Red 36Lake, Red 40 Lake, Yellow 5 Lake, Yellow 6 Lake, Yellow 7 Lake, Yellow10 Lake, and combinations thereof.

Any means known to one of skill in the art capable of producingsufficient force to break the capsules can be used in the presentdisclosure. In one embodiment, the microencapsulated heat deliveryvehicles can be broken by the user at the point of dispensing the wipefrom a package. For example, a mechanical device located inside of thepackage containing the wipes can produce a rupture force sufficient torupture the capsules upon dispensing the wipe, thereby exposing thecontents of the microencapsulated heat delivery vehicles.

In another embodiment, the capsules can be broken by the user just priorto or at the point of use of the wipe. By way of example, in oneembodiment, the force produced by the hands of the user of the wipe canbreak the capsules, exposing the contents of the microencapsulated heatdelivery vehicles.

Under certain conditions, such as in high ambient temperatureconditions, the self-warming wipes of the present disclosure may beperceived by the user as uncomfortably warm. Conversely, theself-warming wipe may begin cooling prior to the end use of the wipe.Since the self-warming wipes are manufactured to provide a designatedtemperature rise, one or more phase change materials may optionally beincluded in the wipe to provide thermal stability to the wipe when thewipe is subjected to extreme heat.

The phase change materials use their heat of fusion to automaticallyregulate the temperature of the self-warming wipe. As well known in theart, “heat of fusion” is the heat in joules required to convert 1.0 gramof a material from its solid form to its liquid form at its meltingtemperature. Accordingly, if the contents of the microencapsulated heatdelivery vehicle are activated and the temperature of the wipe reachesor exceeds the melting point of the phase change material, the phasechange material will liquefy, thereby absorbing the heat from the wipe.Once the wipe begins to cool, the phase change material will resolidifyby releasing the absorbed heat. In one embodiment, to provide thermalstability to the wipe, the phase change material can suitably liquefyand resolidify for one cycle. In another embodiment, such as duringtransportation where the temperature of the wipe can fluctuate, thephase change material undergoes multiple cycles of liquefying andresolidifying.

Suitably, the wipes of the present disclosure may comprise one or morephase change materials for regulating the temperature of the wipe. Inone specific embodiment, the wipe comprises a first phase changematerial. In another embodiment, the wipe comprises a first phase changematerial and a second phase change material.

As noted above, the ideal temperature for the wipes of the presentdisclosure is a temperature of from about 30° C. to about 40° C. (86°F.-104° F.). As such, suitable phase change materials for use as thefirst phase change material have a melting point of from about 22° C. toabout 50° C. More suitably, the first phase change material has amelting point of from about 30° C. to about 40° C., and even moresuitably about 35° C.

Additionally, the first phase change materials have a heat of fusionsuitable for regulating the temperature of the self-warming wipes of thepresent disclosure. Suitably, the first phase change materials have aheat of fusion of from about 8.0 joules/gram to about 380 joules/gram.More suitably, the first phase change materials have a heat of fusion offrom about 100 joules/gram to about 380 joules/gram.

Suitable materials for use as the first phase change materials include,for example, n-Tetracosane, n-Tricosane, n-Docosane, n-Heneicosane,n-Eicosane, n-Nonadecane, n-Octadecane, n-Heptadecane, and combinationsthereof.

In one embodiment, a second phase change material can be included toprovide additional protection against the wipe becoming too hot. Thesecond phase change material is different than the first phase changematerial. For example, the second phase change material typically has ahigher melting point as compared to the first phase change material. Byhaving a higher melting point, the second phase change materials arecapable of absorbing heat at a higher temperature level, and as such canprovide improved protection against thermal discomfort of the skin.Specifically, the second phase change materials suitably have a meltingpoint of from about 50° C. to about 65° C., more suitably, from about50° C. to about 60° C.

Suitable materials for the second phase change materials include, forexample, n-Octacosane, n-Heptacosane, n-Hexacosane, n-Pentacosane, andcombinations thereof.

Any of the phase change materials described above can be introduced intothe wipe in solid or liquid form. For example, in one embodiment, thephase change materials are in solid powder form or particles. Suitably,the phase change material particles have a particle size of from about1.0 micrometers to about 700 micrometers. More suitably, the phasechange material particles have a particle size of from about 300micrometers to about 500 micrometers.

In one embodiment, the phase change material particles can bemicroencapsulated. Generally, the phase change material particles can bemicroencapsulated using any method known in the art. In one preferredembodiment, the phase change material particles are microencapsulatedusing the alginate encapsulation method described above for themicroencapsulated heat delivery vehicles. In another embodiment, thephase change material particles are microencapsulated using the fluidbed coating described above for the microencapsulated heat deliveryvehicles. Other suitable means of encapsulating the phase changematerial particles can include, for example, pan coating, annular-jetencapsulation, complex coacervation, spinning-disk coating, andcombinations thereof.

The microencapsulation shell thickness may vary depending upon the phasechange material utilized, and is generally manufactured to allow theencapsulated phase change material particle to be covered by a thinlayer of encapsulation material, which may be a monolayer or thickerlaminate layer, or may be a composite layer. The microencapsulationlayer should be thick enough to resist cracking or breaking of the shellduring handling or shipping of the product. The microencapsulation layershould also be constructed such that atmospheric conditions duringmanufacturing, storage, and/or shipment will not cause a breakdown ofthe microencapsulation layer and result in a release of the phase changematerial.

In another embodiment, the phase change material is in liquid form,specifically, in a liquid coating composition. To produce the liquidcoating composition, the phase change material, preferably in a purepowder form is combined with an aqueous solution. The solution is thenheated to a temperature above the phase change material melting pointand stirred to shear the phase change material to form the liquidcoating composition comprising the liquid phase change material. In onespecific embodiment, the aqueous solution can be the wetting solution ofa wet wipe described herein above.

In one embodiment, once the liquid coating composition is applied to thefibrous sheet material of the wipe, the composition dries and the phasechange materials solidify into small particles that are distributedthroughout the fibrous sheet material of the wipe.

The liquid coating composition may optionally comprise additionalcomponents to improve the properties, such as spreadability andadhesiveness, of the composition. For example, in one embodiment, theliquid coating composition can comprise a tackifier. Using a tackifierwill improve the binding of the liquid coating composition, and inparticular the phase change material, to the fibrous sheet material.

Typically, the phase change material can be embedded inside of thefibrous sheet material or deposited onto the outer surface of thefibrous sheet material. In one embodiment, the phase change material isembedded inside of the fibrous sheet material. The phase change materialcan be embedded into the core of the fibrous sheet material using anymethod described above for embedding the microencapsulated heat deliveryvehicles into the core.

In another embodiment, the phase change material can be deposited on anouter surface of the fibrous sheet material. Typically, the phase changematerial can be deposited on an outer surface of the fibrous sheetmaterial using any method described above for depositing themicroencapsulated heat delivery vehicles on an outer surface of thefibrous sheet material. Similar to the microencapsulated heat deliveryvehicles, when depositing the phase change material, the phase changematerial can be deposited on one outer surface of the fibrous sheetmaterial, or the phase change material can be applied to both outersurfaces of the fibrous sheet material.

In addition to the methods of application described above, the phasechange materials described herein can be applied to the desired area ofthe fibrous sheet material using the methods of spray coating, slotcoating and printing, or a combination thereof. In slot coating, thephase change material is introduced directly onto or into the desiredarea of the fibrous sheet material in “slots,” discrete row patterns, orother patterns. Similar to applying the microencapsulated heat deliveryvehicle in patterns described above, slot coating may be advantageous incertain applications where it is not desirable to coat the entirefibrous sheet material with a phase change material.

The phase change material should suitably be applied to the fibroussheet material similar to the microencapsulated heat delivery vehicle.Specifically, when the microencapsulated heat delivery vehicle isapplied in a continuous layer, the phase change material should beapplied in a continuous layer. Likewise, when the microencapsulated heatdelivery vehicle is applied in a patterned layer, the phase changematerial should be applied in a patterned layer. Suitable patterns forapplying the phase change materials are those patterns described abovefor the microencapsulated heat delivery vehicles. Specifically, thephase change materials can be applied in the patterns including, forexample, stripes, characters, swirls, numbers, dots, and combinationsthereof. Applying the phase change material in a similar manner as themicroencapsulated heat delivery vehicle will allow for the phase changematerial to more easily and efficiently absorb the heat generated by themicroencapsulated heat delivery vehicle, thus, providing betterprotection against thermal discomfort to the user of the wipe.

The amount of phase change material to be applied to the fibrous sheetmaterial will depend upon the desired temperature increase of the wipe,the type of microencapsulated heat delivery vehicle used, the amount ofmicroencapsulated heat delivery vehicle used, and the type of phasechange material used. In one embodiment, when all of the heat generatedby the heating agent is absorbed by the wipe, the formula forcalculating the amount of phase change material required for use in thewipe is as follows:m _((PCM)) =[ΔH _((HA)) ×m _((HA)) ]/ΔH _((PCM))

wherein m_((PCM)) is the required mass of phase change material;ΔH_((HA)) is the heat of solution or the heat generated by themicroencapsulated heat delivery vehicle, per unit mass; m_((HA)) is themass of the microencapsulated heat delivery vehicle used; and ΔH_((PCM))is the heat of fusion of the phase change material, per unit mass.

As noted above, in one specific embodiment, the microencapsulated heatdelivery vehicles as described herein are suitable for combination witha biocide agent for use in cleansing compositions, which may be usedalone, or in combination with a cleansing product such as a wipe.Generally, the cleansing composition includes the microencapsulated heatdelivery vehicle as described above and a biocide agent and is suitablefor cleaning both animate and inanimate surfaces.

Using the microencapsulated heat delivery vehicles in the cleansingcomposition in combination with the biocide agents results in anincreased biocidal effect when the microencapsulated heat deliveryvehicles are activated. Specifically, the increase in temperature hasbeen found to activate or enhance the function of the biocide agentspresent in the cleansing composition.

Generally, the three main factors affecting the efficacy of biocideagents include: (1) mass transfer of biocide agents in the cleansingcomposition to the microbe-water interface; (2) chemisorption of biocideagents to the cell wall or cell membrane of the microbes; and (3)diffusion of the activated chemisorbed biocide agent into the cell ofthe microbe. It has been found that temperature is a primary regulatorof all three factors. For example, the lipid bilayer cell membranestructure of many microbes “melts” at higher than room temperatures,allowing holes to form in the membrane structure. These holes can allowthe biocide agent to more easily diffuse through the microbe cell wallor membrane and enter the cell.

Generally, the cleansing compositions of the present disclosure arecapable of killing or substantially inhibiting the growth of microbes.Specifically, the biocide agent of the cleansing compositions interfaceswith either the reproductive or metabolic pathways of the microbes tokill or inhibit the growth of the microbes.

Microbes suitably affected by the biocide agents of the cleansingcomposition include viruses, bacteria, fungi, and protozoans. Virusesthat can be affected by the biocide agents include, for example,Influenza, Parainfluenza, Rhinovirus, Human Immunodeficiency Virus,Hepatitis A, Hepatitis B, Hepatitis C, Rotavirus, Norovirus, Herpes,Coronavirus, and Hanta virus. Both gram positive and gram negativebacteria are affected by the biocide agents of the cleansingcomposition. Specifically, bacteria affected by the biocide agents usedin the cleansing compositions include, for example, Staphylococcusaureus, Streptococcus pneumoniae, Streptococcus pyogenes, Pseudomonasaeruginose, Klebsiella pneumoniae, Escherichia coli, Enterobacteraerogenes, Enterococcus faecalis, Bacillus subtilis, Salmonella typhi,Mycobacterium tuberculosis, and Acinetobacter baumannii. Fungi affectedby the biocide agents include, for example, Candida albicans,Aspergillus niger, and Aspergillus fumigates. Protozoans affected by thebiocide agents include, for example, cyclospora cayetanensis,Cryptosporidum parvum, and species of microsporidum.

Suitable biocide agents for use in the cleansing compositions include,for example, isothiazolones, alkyl dimethyl ammonium chloride,triazines, 2-thiocyanomethylthio benzothiazol, methylene bisthiocyanate, acrolein, dodecylguanidine hydrochloride, chlorophenols,quarternary ammonium salts, gluteraldehyde, dithiocarbamates,2-mercaptobenzothiazole, para-chloro-meta-xylenol, silver,chlorohexidine, polyhexamethylene biguanide, n-halamines, triclosan,phospholipids, alpha hydroxyl acids, 2,2-dibromo-3-nitrilopropionamide,2-bromo-2-nitro-1,3-propanediol, farnesol, iodine, bromine, hydrogenperoxide, chlorine dioxide, alcohols, ozone, botanical oils (e.g., teetree oil and rosemary oil), botanical extracts, benzalkonium chloride,chlorine, sodium hypochlorite, and combinations thereof.

The cleansing compositions of the present disclosure may also optionallycontain a variety of other components which may assist in providing thedesired cleaning properties. For example, additional components mayinclude non-antagonistic emollients, surfactants, preservatives,chelating agents, pH adjusting agents, fragrances, moisturizing agents,skin benefit agents (e.g., aloe and vitamin E), antimicrobial actives,acids, alcohols, or combinations or mixtures thereof. The compositionmay also contain lotions, and/or medicaments to deliver any number ofcosmetic and/or drug ingredients to improve performance.

The cleansing compositions of the present disclosure are typically insolution form and include water in an amount of about 98% (by weight).The solution can suitably be applied alone as a spray, lotion, foam, orcream.

When used as a solution, the biocide agents are typically present in thecleansing composition in an amount of from about 3.0×10⁻⁶% (by weight)to about 95% (by weight). Suitably, the biocide agents are present inthe cleansing composition in an amount of from about 0.001% (by weight)to about 70.0% (by weight), even more suitably from about 0.001% (byweight) to about 10% (by weight), and even more suitably in an amount offrom about 0.001% (by weight) to about 2.0% (by weight).

When used in combination with the biocide agent in the solution ofcleansing composition, the microencapsulated heat delivery vehicles asdescribed above are suitably present in the cleansing compositions in anamount of from about 0.05% (by weight cleansing composition) to about25% (by weight cleansing composition). More suitably, themicroencapsulated heat delivery vehicles are present in the cleansingcompositions in an amount of from about 1.0% (by weight cleansingcomposition) to about 25% (by weight cleansing composition).

In another embodiment, the cleansing composition is incorporated into asubstrate which can be a woven web, non-woven web, spunbonded fabric,meltblown fabric, knit fabric, wet laid fabric, needle punched web,cellulosic material or web, and combinations thereof, for example, tocreate products such as hand towels, bathroom tissue, dry wipes, wetwipes, and the like. In one preferred embodiment, the cleansingcomposition is incorporated into the wet wipe described above.

Typically, to manufacture the wet wipe with the cleansing composition,the microencapsulated heat delivery vehicle and biocide agent can beembedded inside of the fibrous sheet material or deposited on the outersurface of the fibrous sheet material. In one embodiment, themicroencapsulated heat delivery vehicle and biocide agent are bothembedded inside of the fibrous sheet material. The microencapsulatedheat delivery vehicle can be embedded inside of the fibrous sheetmaterial as described above. Additionally, the biocide agent can beembedded inside of the fibrous sheet material using any method describedabove for embedding the microencapsulated heat delivery vehicle into thecore.

In another embodiment, both the microencapsulated heat delivery vehicleand the biocide agent are deposited on an outer surface of the fibroussheet material. The microencapsulated heat delivery vehicle can bedeposited on one or both outer surfaces of the fibrous sheet material asdescribed above. Typically, the biocide agent can be deposited on anouter surface of the fibrous sheet material using any method describedabove for depositing the microencapsulated heat delivery vehicle on anouter surface of the fibrous sheet material. Similar to themicroencapsulated heat delivery vehicle, when depositing the biocideagent, the biocide agent can be deposited on one outer surface of thefibrous sheet material, or the biocide agent can be applied to bothouter surfaces of the fibrous sheet material.

In yet another embodiment, the microencapsulated heat delivery vehiclecan be embedded into the core of the fibrous sheet material using anymethod described above and the biocide agent can be deposited on one orboth outer surfaces of the fibrous sheet material using any methoddescribed above.

In addition to the methods of application described above, the biocideagents described herein can be applied to the desired area of thefibrous sheet material using the methods of spray coating, slot coatingand printing, and combinations thereof.

In one embodiment, the biocide agents can be microencapsulated in ashell material prior to being introduced into or onto the fibrous sheetmaterial. Generally, the biocide agent can be microencapsulated usingany method known in the art. Suitable microencapsulation shell materialsinclude cellulose-based polymeric materials (e.g., ethyl cellulose),carbohydrate-based materials (e.g., cationic starches and sugars) andmaterials derived therefrom (e.g., dextrins and cyclodextrins) as wellas other materials compatible with human tissues.

The microencapsulation shell thickness may vary depending upon thebiocide agent utilized, and is generally manufactured to allow theencapsulated formulation or component to be covered by a thin layer ofencapsulation material, which may be a monolayer or thicker laminatelayer, or may be a composite layer. The microencapsulation layer shouldbe thick enough to resist cracking or breaking of the shell duringhandling or shipping of the product. The microencapsulation layer shouldalso be constructed such that atmospheric conditions duringmanufacturing, storage, and/or shipment will not cause a breakdown ofthe microencapsulation layer and result in a release of the biocideagent.

Microencapsulated biocide agents applied to the outer surface of thewipes as discussed above should be of a size such that the user cannotfeel the encapsulated shell on the skin during use. Typically, thecapsules have a diameter of no more than about 25 micrometers, anddesirably no more than about 10 micrometers. At these sizes, there is no“gritty” or “scratchy” feeling on the skin when the wipe is utilized.

When used in a product such as a wipe, the microencapsulated heatdelivery vehicles are present in the fibrous sheet material in an amountsuitably of from about 0.33 grams per square meter to about 500 gramsper square meter microencapsulated heat delivery vehicle. More suitably,the wipes comprise from about 6 grams per square meter to about 175grams per square meter microencapsulated heat delivery vehicle, and evenmore suitably, from about 16 grams per square meter to about 75 gramsper square meter microencapsulated heat delivery vehicle.

Suitably, the biocide agent is present in the fibrous sheet material ofthe wet wipe in an amount of suitably 0.01 grams per square meter toabout 50 grams per square meter. More suitably, the biocide agent ispresent in the fibrous sheet material in an amount of from about 0.01grams per square meter to about 25 grams per square meter, and even moresuitably, in an amount of from about 0.01 grams per square meter toabout 0.1 grams per square meter.

The present disclosure is illustrated by the following examples whichare merely for the purpose of illustration and are not to be regarded aslimiting the scope of the disclosure or manner in which it may bepracticed.

EXAMPLE 1

In this example, samples incorporating various size ranges of anhydrouscalcium chloride suspended in mineral oil at 35 wt % were evaluated fortheir ability to generate heat upon introduction into water.

The five size ranges of anhydrous calcium chloride evaluated were: (1)less than 149 microns; (2) 149-355 microns; (3) 710-1190 microns; (4)1190-2000 microns; and (5) 2000-4000 microns. The samples of anhydrouscalcium chloride (Dow Chemical, Midland, Mich.) were dispersed inmineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson,Tex.). The as received anhydrous calcium chloride were screened dryusing a Gilson Sonic Sieve (Gilson Company, Inc. Columbus, Ohio) tocreate two sizes, a 1190-2000 micron size and a 2000-4000 micron size.These powders were then suspended at 35 wt % in mineral oil to form aslurry using a cowles mixing blade. To achieve the smaller sizedistributions, the anhydrous calcium chloride powder required furtherprocessing.

Specifically, the sample of anhydrous calcium chloride having a sizerange of 710-1190 microns was produced by grinding the as receivedanhydrous calcium chloride with a size range of 2000-4000 microns in ahammermill, screening the powder to the desired size, and thensuspending the calcium chloride particles at 35 wt % in mineral oilusing a cowles mixing blade. The sample of anhydrous calcium chloridehaving a size range of 149-355 microns was produced by grinding the asreceived anhydrous calcium chloride with a size range of 2000-4000microns in a hammermill, suspending the calcium chloride particles at 35wt % in mineral oil using a cowles mixing blade and then furtherprocessing this slurry in a Buhler K8 media mill (Buhler, Inc.Switzerland). This media milling process used 0.5 millimeter aluminagrinding media, and rotated at a speed of 1800 revolutions per minute(rpm), for 1.5 hours while slurry was pumped through the millingchamber. While being milled, 0.5 wt % surfactant, available as Antiterra207 (BYK-Chemie, Wesel, Germany) was mixed with the anhydrous calciumchloride to control the viscosity. The sample of anhydrous calciumchloride having a size range of less than 149 microns was produced bygrinding the as received anhydrous calcium chloride with a size range of2000-4000 microns in a hammermill, suspending the calcium chlorideparticles at 35 wt % in mineral oil using a cowles mixing blade and thenfurther processing this slurry in a Buhler K8 media mill (Buhler, Inc.Switzerland). This media milling process used 0.5 millimeter aluminagrinding media, and rotated at a speed of 1800 revolutions per minute(rpm), for 2.5 hours while slurry was pumped through the millingchamber. While being milled, 0.5 wt % surfactant, available as Antiterra207 (BYK-Chemie, Wesel, Germany) was mixed with the anhydrous calciumchloride to control the viscosity.

All five samples were then individually added to 7.0 grams de-ionizedwater and the resulting temperature rise was measured using a BarnantScanning Thermocouple (available from Therm-X of California, Hayward,Calif.). The results are shown in FIG. 3.

As shown in FIG. 3, although all samples delivered an increase in therate of heat release, the sample using anhydrous calcium chloride havinga particle size in the range of 149-355 micrometers generated heat atthe highest rate.

EXAMPLE 2

In this example, samples incorporating various size ranges of anhydrousmagnesium chloride suspended in mineral oil at 35 wt % were evaluatedfor their ability to generate heat upon introduction into water.

The four size ranges of anhydrous magnesium chloride evaluated were: (1)1000-1500 microns; (2) 600-1000 microns; (3) 250-600 microns; and (4)less than 250 microns. To produce the samples of anhydrous magnesiumchloride in mineral oil, the various size ranges of anhydrous magnesiumchloride powder (Magnesium Interface Inc. (Vancouver, B.C., Canada) weresuspended at 35 wt % in mineral oil (available as Drakeol 7 LT NF fromPenreco, Dickinson, Tex.). To produce the samples having anhydrousmagnesium chloride with size ranges of 1000-1500 microns, 600-1000microns, and 250-600 microns, the as received anhydrous magnesiumchloride powder was hand screened into the size ranges desired and thepowders collected. These powders were suspended at 35 wt % in mineraloil using a cowles mixing blade. The sample of anhydrous magnesiumchloride having a size range of less than 250 microns was produced bycoffee grinding (Mr. Coffee Grinder No. 10555, Hamilton Beach) theanhydrous magnesium chloride having a size range of 1000-1500 micronsfor 30 seconds to reduce the size. This sample was then processed usinga Gilson Sonic Sieve (Gilson Company, Inc., Columbus, Ohio) to collectthe particles having a particle size of less than 250 microns. Thispowder was suspend at 35 wt % in mineral oil using a cowles mixingblade.

All four samples were then added to 7.0 grams de-ionized water and theresulting temperature rise was measured using a J type Thermocouple(available from Omega Engineering, Inc., Stamford, Conn.). The resultsare shown in FIG. 4.

As shown in FIG. 4, although all samples delivered an increase in therate of heat release, the sample using anhydrous magnesium chloridehaving a particle size of less than 250 micrometers generated heat atthe highest rate.

EXAMPLE 3

In this Example, six compositions including a heating agent, matrixmaterial, and various surfactants were produced. The viscosities (at 23°C.) of the compositions were measured using a Brookfield Viscometer todetermine which surfactants were preferred for use in the compositionsof the present disclosure.

To produce the compositions, 34.7% (by weight composition) anhydrousmagnesium chloride (available from Magnesium Interface Inc., Vancouver,B.C., Canada), 64.3% (by weight composition) mineral oil (available asDrakeol 7 LT NF from Penreco, Dickinson, Tex.), and 1.0% surfactant (byweight composition) were milled together using a vertical attritor millusing one quarter inch, spherical, ceramic media for a total of 90minutes. The surfactants utilized in the six compositions and theirproperties are shown in Table 1.

TABLE 1 Commercial Ionic Surfactant Source Activity Antiterra 207 BYKChemie Anionic (Wesel, Germany) Disperbyk 166 BYK Chemie Proprietary(Wesel, Germany) Disperbyk 162 BYK Chemie Cationic (Wesel, Germany)BYK-P104 BYK Chemie Anionic (Wesel, Germany) Tergitol TMN-6 UnionCarbide Non-ionic (Houston, HLB = 11.7 Texas) Span 85 Uniqema/ICINon-ionic Surfactants HLB = 1.8 (Malaysia)

The viscosities of the compositions (at 23° C.) were measured using aBrookfield Viscometer having a spindle rotating at 100 revolutions perminute (rpm). The results are shown in Table 2.

TABLE 2 Spindle Number of Surfactant Viscosity at 23° C. (cP) ViscometerAntiterra 208 RU3 207 Disperbyk 208 RU3 166 Disperbyk 1366 RU6 162BYK-P104 306 RU3 Tergitol 7120 RU6 TMN-6 Span 85 352 RU3

Samples with the lower viscosities are better suited for use incompositions utilized to make the microencapsulated heat deliveryvehicles of the present disclosure as these compositions are easier towork with and allow for higher loading of heating agents. As such, asshown in Table 2, the compositions made with Antiterra 207 and BYK-P104have the lowest viscosities, and as such, would be preferred surfactantsfor use in some of the compositions of the present disclosure. Moreover,the composition made with Tergitol TMN-6 had the highest viscosity andwould thus be a less preferred surfactant for use in the compositions ofthe present disclosure.

EXAMPLE 4

In this Example a microencapsulated heat delivery vehicle wasmanufactured utilizing calcium chloride as both the encapsulatingactivator and the heating agent.

Calcium chloride (about 20 micrometers in diameter) was introduced intomineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson, Tex.)to form a 25% (by weight) calcium chloride in mineral oil compositionthat was mixed together thoroughly and had a resulting viscosity (25°C.) of about 300 centipoise. This composition was introduced dropwisefrom a separatory funnel into two liters of an Manugel DMB aqueoussodium alginate solution (1% by weight in deionized water, 300centipoise at 25° C., available from ISP Technologies, Inc., Scotland)and allowed to dwell in the solution for about 30 minutes undersufficient stirring to keep the drops formed upon addition into thesodium alginate solution separate. It is also significant to avoidoverstirring, as this can cause high excess calcium release and alginatebroth gelation. Most drops of the composition added were between about 3millimeters in diameter and about 5 millimeters in diameter. After 30minutes dwell time the formed microencapsulated beads were removed fromthe sodium alginate solution and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated heat delivery vehicles were formed.

EXAMPLE 5

In this Example a microencapsulated heat delivery vehicle includingmagnesium oxide was manufactured utilizing calcium chloride as theencapsulating activator.

Calcium chloride (about 20 micrometers in diameter) was introduced into133 grams of propylene glycol and 70 grams of magnesium oxide to form a3% (by weight) calcium chloride composition that was mixed togetherthoroughly and had a resulting viscosity (25° C.) of about 500centipoise. This composition was introduced dropwise from a separatoryfunnel into two liters of an aqueous sodium alginate solution (1% byweight in de-ionized water, 250 centipoise at 25° C.) and allowed todwell in the solution for about 30 minutes under sufficient stirring tokeep the drops formed upon addition into the sodium alginate solutionseparate. It is also significant to avoid overstirring, as this cancause high excess calcium release and alginate broth gelation. Mostdrops of the composition added were between about 3 millimeters indiameter and about 5 millimeters in diameter. After 30 minutes dwelltime the formed microencapsulated beads were removed from the sodiumalginate solution and rinsed three times with de-ionized water and castto air-dry overnight at room-temperature. Stable microencapsulated heatdelivery vehicles were formed.

EXAMPLE 6

In this Example, a microencapsulated heat delivery vehicle includingcalcium chloride as the encapsulating activator was produced.

Calcium chloride (about 20 micrometers in diameter) was introduced intomineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson, Tex.)to form a 25% (by weight) calcium chloride composition that was mixedtogether thoroughly and had a resulting viscosity (25° C.) of about 300centipoise. This composition was introduced dropwise from a separatoryfunnel into one half liter of an anionic water dispersedbutadiene/acrylonitrile latex emulsion (100 grams of Eliochem ChemigumLatex 550 (commercially available from Eliochem, France) dissolved in500 grams of de-ionized water) and allowed to dwell in the solution forabout 10 minutes under sufficient stirring to keep the drops formed uponaddition into the latex emulsion solution separate. Most drops of thecomposition added were between about 3 millimeters in diameter and about5 millimeters in diameter. During a 30-minute dwell time, themicroencapsulated beads were formed in a latex shell. These beads wereremoved from the latex emulsion and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated vehicles were formed.

EXAMPLE 7

In this Example a microencapsulated heat delivery vehicle including afragrance oil was manufactured utilizing calcium chloride as theencapsulating activator.

A mixture (1 gram) of 25% (by weight) calcium chloride and 75% (byweight) mineral oil (available as Drakeol 7 LT NF from Penreco,Dickinson, Tex.) was added to 9 grams of Red Apple Fragrance Oil(commercially available from Intercontinental Fragrances, Houston, Tex.)and the resulting composition thoroughly mixed. The resultingcomposition was added dropwise from a separatory funnel to a 1% (byweight) sodium alginate in de-ionized water solution and allowed todwell in the solution for about 20 minutes under sufficient stirring tokeep the drops formed upon addition to the sodium alginate solutionseparate. It is also significant to avoid overstirring, as this cancause high excess calcium release and alginate broth gelation. After the20 minute dwell time, the formed microencapsulated beads were removedfrom the sodium alginate solution and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated vehicles were formed.

EXAMPLE 8

In this Example, a microencapsulated heat delivery vehicle including aheating agent surrounded by a hydrophobic wax material was producedusing a method of the present disclosure. This microencapsulated heatdelivery vehicle was then analyzed to determine its ability to generateheat after being contacted with water as compared to a control sample,which was a microencapsulated heat delivery vehicle including a heatingagent not surrounded by a hydrophobic wax material.

To produce the heating agent surrounded by a hydrophobic wax materialfor inclusion in the microencapsulated heat delivery vehicle, 100 gramsof a hydrophobic wax material, available as Polywax 500 fromFischer-Tropsch Wax Products (Sugar Land, Tex.) was melted in a steelbeaker at a temperature of about 110° C. and thoroughly mixed with 200grams anhydrous magnesium chloride salt grains (available from MagnesiumInterface Inc., Vancouver, B.C., Canada) having a particle size of about100 micrometers. The agglomerated mass was allowed to cool to roomtemperature. A coffee grinder (commercially available as Mr. Coffee®Grinder from Hamilton Beach) was then used to break the mass intoparticles having a particle size of approximately 3 micrometers to 5micrometers in diameter. A portion of these particles was introducedinto water and found not to be soluble. This indicated the presence of acontinuous wax coating surrounding the magnesium chloride.

Thirty grams of wax-coated magnesium chloride was added to a 30-gramsuspension of 10% (by weight) calcium chloride/25% (by weight) magnesiumchloride/65% (by weight) mineral oil to make a paste. The paste wasadded slowly to 2 liters of a 0.5% (by weight) aqueous sodium alginatesolution. Using an overhead stirrer rotating at 700 revolutions perminute (rpm), the paste was broken down into emulsion forming beadshaving a diameter of about 2 millimeters. The beads were allowed todwell for approximately 10 minutes in the high shear aqueous environmentto form a crosslinked alginate shell. After 10 minutes, the beads wereremoved and rinsed with de-ionized water.

Three grams of the microencapsulated heat delivery vehicles were crushedin the presence of 7.0 grams water to determine the ability of themicroencapsulated heat delivery vehicles to generate heat. Thetemperature of the water increased by approximately 10° C.

A control sample was then produced and compared to the microencapsulatedheat delivery vehicles produced above. To produce the control sample, a5% (by weight) calcium chloride/25% (by weight) magnesium chloride/70%(by weight) mineral oil paste was produced as described above with theexception that there was not any wax coated magnesium chloride. Theresulting beads were then crushed in the presence of 7.0 grams water.With the control sample, a temperature increase of approximately 5° C.was detected.

The results show that the heat of hydration and heat of solution of theanhydrous magnesium chloride of the microencapsulated heat deliveryvehicle including a heating agent surrounded by a hydrophobic waxmaterial was maintained, while the magnesium chloride of the controlsample was deactivated either during the high shearemulsion/encapsulation processes or in the rinsing and drying of thebeads.

EXAMPLE 9

In this Example, a microencapsulated heat delivery vehicle including aheating agent surrounded by a hydrophobic wax material was produced.This microencapsulated heat delivery vehicle was analyzed to determineits ability to generate heat upon contact with water.

To produce the heating agent surrounded by a hydrophobic wax material, ablend of 95% (by weight) anhydrous magnesium chloride (available fromMagnesium Interface Inc., Vancouver, B.C., Canada) and 5% (by weight)Polywax 500 (available from Fischer-Tropsch Wax Products, Sugar Land,Tex.) was prepared by heating 500 grams of the blend to a temperature of110° C. in a closed container. The blend was periodically stirred over a2-hour period. While still hot, 4-millimeter ceramic milling media(Dynamic Ceramic, United Kingdom) were added to the container and rolledon a jar mill until the blend cooled to room temperature.

Fifty grams of the 95% (by weight) anhydrous magnesium chloride/5% (byweight) wax blend was added to 50 grams of a composition comprising 10%(by weight) calcium chloride and 90% (by weight) mineral oil. Theresulting paste was added slowly into 2 liters of a 0.5% (by weight)aqueous sodium alginate solution. Using an overhead stirrer rotating at650 rpm, the paste was broken down into emulsion forming beads having adiameter of between about 2 to 4 millimeters. The beads were allowed todwell for approximately 10 minutes in the high shear aqueous environmentto form a crosslinked alginate shell. After 10 minutes the beads wereremoved and rinsed with water.

Three grams of the microencapsulated heat delivery vehicle were crushedin the presence of 7.0 grams water to determine the ability of themicroencapsulated heat delivery vehicle to generate heat. Thetemperature of the water increased by approximately 18° C. indicatingthat the wax coating protected the heating agent during the aqueouscrosslinking process.

EXAMPLE 10

In this Example, spherical core materials containing a water solublematerial were encapsulated with a moisture protective layer. Thesesamples were then added to low conductivity water and the conductivityof this solution was monitored over time to compare the behavior ofmoisture protected and unprotected particles.

To produce the spherical core material including a moisture protectivelayer, 7.0 grams of approximately 2-millimeter sized beads containing 80wt % wax (available as Dritex C from Dritex International Limited,Essex, United Kingdom) and 20 wt % sodium sulfate (a water solublematerial) were formed in the following manner. Dritex C wax and sodiumsulfate were melted to 100° C. in a pressure pot. A standard prillingprocess was used to form the beads wherein the melted composition wassprayed out of a single nozzle fluid and the 2 millimeter beads werecollected. To form the moisture protective layer, 7 grams of these beadswere introduced into a glass beaker. Using a dropper, 0.295 grams ofPluracol GP-430, which is a polyol, available from BASF Corporation(Wyandotte, Mich.), was added to the glass beaker. The mixture was handstirred using a spatula for about 5 minutes to fully coat the corematerial. After stirring the mixture, 0.314 grams Lupranate M20-S, whichis a polyether polyol available from BASF Corporation (Wyandotte,Mich.), was added to the mixture using a dropper. The mixture, includingthe Lupranate, was hand stirred using a spatula for about 15 minutes.The mixture was then allowed to oven cure at 60° C. for 15 minutes toform the moisture protective layer on the spherical core material.

2.0 grams of core material particles were added to 120 grams ofdeionized water in a 150 milliliter beaker. The conductivity of thedeionized water was then measured as a function of time using an Orionmodel 135 Waterproof Conductivity/TDS/Salinity/Temperature Meter(Fischer Scientific). The conductivity of the control sample (sphericalcore material without any moisture protective coating was also analyzed.The results are shown in FIG. 5.

As shown in FIG. 5, the core material particles with a protective layerhave a slower rate of conductivity increase over non protectedmaterials. It is advantageous to have a low release of water sensitivematerials to insure moisture protection of the core material.

EXAMPLE 11

In this Example, anhydrous calcium chloride particles were treated toimpart a moisture protective layer thereon. The ability of the calciumchloride particles including the moisture protective layer to generateheat after contact with water was analyzed and compared to a controlsample, which included calcium chloride particles without a moistureprotective layer.

To impart the moisture protective layer onto the calcium chlorideparticles, 250 grams anhydrous calcium chloride with a particle size ofabout 2 millimeters (available from The Dow Chemical Company, Midland,Mich.) were added to a V-blender, rotating at a speed of 62 revolutionsper minute (rpm) and maintained at a temperature of 60° C. Rotation ofthe V-blender was stopped and a dropper was used to add 2.50 grams ofPluracol GP 430, a polyol available from BASF Corporation (Wyandotte,Mich.) to form a mixture of anhydrous calcium chloride and Pluracol GP430. The mixture was blended in the V-blender for approximately oneminute. The V-blender was again stopped and 2.50 grams Lupranate M20-S,a polyether polyol available from BASF Corporation (Wyandotte, Mich.),was added. The mixture was blended for about 10 minutes. After blendingthe mixture, about 2.50 grams of refined yellow #1 Carnauba wax,available from Sigma-Aldrich Co. (St. Louis, Mo.) was added and theblender again started. The temperature of the mixture in the blender wasincreased to 95° C. The blending was continued for about 15 minutes at95° C. The blending was stopped and the mixture was allowed to cool toambient temperature.

A second addition of Pluracol GP 430, Lupranate M20-S, and yellow #1Carnauba wax was added to the blended mixture in the same manner asdescribed above. Additionally, a third addition of Pluracol GP 430 andLupranate was added and blended as described above. After blending themixture, the mixture was allowed to oven cure at 60° C. for 15 minutes.The mixture was allowed to cool and sealed in a jar. After 24 hours, theyellow #1 Carnauba wax was added to the cooled mixture in the mannerdescribed above and the mixture was again allowed to cool to form themicroencapsulated heat delivery vehicle including a moisture protectivelayer.

Four samples of the calcium chloride particles including a moistureprotective layer were then analyzed for their ability to generate heatafter exposure to water. A control sample (calcium chloride) was alsotested for heat generating capabilities and compared to the four samplesof calcium chloride having a moisture protective layer.

To analyze the samples for heat generation, 0.80 grams of each sample ofcalcium chloride including a moisture protective layer was added to fourseparate vials each containing 7.0 grams of de-ionized water and 0.73grams of the control sample was added to a fifth vial containing 7.0grams of de-ionized water. Using a J type thermocouple (commerciallyavailable from Omega Engineering, Inc., Stamford, Conn.) and a datalogger, the temperature of the samples was measured over a period of 180seconds. The four vials containing the samples of microencapsulated heatdelivery vehicle including a moisture protective layer were allowed toremain in the de-ionized water for 0.5 hours, 1.0 hour, 1.5 hours, and2.0 hours, respectively, at which time the samples were activated bycrushing the samples by hand using a metal rod. The temperature of thewater in the four vials was measured for a period of 180 seconds aftercrushing the samples. The results are shown in FIG. 6.

As shown in FIG. 6, the samples of microencapsulated heat deliveryvehicles including a moisture protective layer continued to produce heatafter soaking in de-ionized water after two hours. The control samplehaving no protective layer, however, produced heat immediately uponbeing introduced into water but only for a short period of time.

EXAMPLE 12

In this Example, microencapsulated heat delivery vehicles including amoisture protective layer comprising various amounts of a mixture ofSaran F-310 and polymethylmethacrylate were produced. The samples werethen evaluated for water barrier properties by soaking the samples in awetting solution at a temperature of approximately 50° C., and thensubmitting the samples to a heat test.

Three levels of moisture protective layer on the microencapsulated heatdelivery vehicles were evaluated: (1) 17% (by weight microencapsulatedheat delivery vehicle); (2) 23% (by weight microencapsulated heatdelivery vehicle; and (3) 33% (by weight microencapsulated heat deliveryvehicle). To produce the Saran F-310/polymethylmethacrylate solution forapplication to the microencapsulated heat delivery vehicles to form themoisture protective layer, 80 grams Saran F-310, available from DowChemical Company (Midland, Mich.) was dissolved in a 320-gram solutionof 70% (by weight) methyl ethyl ketone (MEK) and 30% (by weight)toluene, and 20 grams polymethylmethacrylate was dissolved in 180 gramsacetone. The Saran F-310 and polymethylmethacrylate solutions were thenblended together to produce a solution comprising 20% (by weight) solidswherein 90% (by weight solids) was Saran F-310 and 10% (by weightsolids) was polymethylmethacrylate (treatment solution).

Once the treatment solution was produced, the microencapsulated heatdelivery vehicles including the desired amounts of moisture protectivelayer were produced. First, in order to provide a continuous layer ofshell material at the “base” or bottom of the microencapsulated heatdelivery vehicles, a glass syringe was used to apply 1.5 grams of thetreatment solution to a sheet of Saran film, which had been stretchedover a flat surface (17″×22″ metal sheet). The treatment solution wasallowed to dry until it reached the tacky stage. The Saran film surfacewas marked with circles of approximately three inches in diameter inorder to be used as a guide and to facilitate even coating of the shellmaterial. For the 17% (by weight) coating, three grams ofmicroencapsulated heat delivery vehicles as produced in Example 8 werethen placed in an aluminum weigh pan and blended with 1.5 grams of thetreatment solution until the beads were well coated. Using a scoopula,the beads were stirred in the solution until well coated. The coatedbeads were then poured with the remaining treatment solution onto thebase coat layer on the Saran film and allowed to dry completely.

The samples including 23% (by weight) moisture protective layer wereproduced using the method described above with the exception of using2.25 grams of the treatment solution instead of 1.5 grams of treatmentsolution.

To produce the samples including 33% (by weight) shell material, twobase coats were produced using the method described above, eachcomprising 1.9 grams of treatment solution. The first base coat wasallowed to dry prior to applying the second base coat. Three grams ofthe alginate beads were blended with 1.9 grams of treatment solution inthe aluminum weigh pan. The coated microencapsulated heat deliveryvehicles were then poured onto the base coat layers and allowed to dryto the tacky stage. An additional 1.9 grams of treatment solution wasapplied over the coated alginate beads and allowed to completely dry.

Sixteen samples of each coating amount were then analyzed for theirability to generate heat after being immersed in the wetting solutionand held at a temperature of 50° C. for various lengths of time rangingfrom 0 to 14 days. To analyze the samples, 3.0 grams of each sample areadded to an empty balloon. A wetting solution (7 grams) comprising: 98%(by weight) water, 0.6% (by weight) potassium laureth phosphate, 0.3%(by weight) glycerin, 0.3% (by weight) polysorbate 20, 0.2% (by weight)tetrasodium EDTA, 0.2% (by weight) DMDM hydantoin, 0.15% (by weight)methylparaben, 0.07% (by weight) malic acid, 0.001% (by weight) aloebarbadensis, and 0.001% (by weight) tocopheryl acetate. A thermocoupleis then introduced into the balloon to monitor the temperature. Thesample beads were then activated by hand crushing the beads and thetemperature increase is measured. The results for each coating amountwere averaged and shown in FIG. 7.

EXAMPLE 13

In this Example, samples of microencapsulated heat delivery vehiclesincluding non-polymeric moisture protective layers were produced usingelectroless silver plating on microencapsulated heat delivery vehicles.The samples were then analyzed for their ability to generate heat.

To produce the electroless silver coating solutions, a sensitizersolution, reducer solution, and silver coating solution were produced.The sensitizer solution was produced by adding 4.8 grams of 22° BaumeHCl (Fischer Scientific Technical Grade) to 946 milliliters ofde-ionized water. 10 grams of 98% (by weight) stannous chloride,available from Sigma-Aldrich Co. (St. Louis, Mo.) was then added to thesolution. To produce the reducer solution, 170 grams dextrose wasdissolved in 946 milliliters de-ionized water. To produce the silvercoating solution, 10 grams potassium hydroxide was dissolved in 3 litersof de-ionized water. Once dissolved, 50 milliliters of ammoniumhydroxide was added to the solution and then finally, 25 grams of silvernitrate was added during vigorous agitation using a 3 blade-2 stirrermixer, mixing at about 2000 revolutions per minute (rpm). The agitationwas continued until the brown precipitate was re-dissolved. De-ionizedwater was added to the mixture in an amount to produce one gallon ofsilver coating solution.

Prior to coating the microencapsulated heat delivery vehicles asdescribed below, the vehicles were analyzed to determine their abilityto generate heat as measured in Example 12 above.

Fifteen grams of microencapsulated heat delivery vehicles as made inExample 8 were placed into a quart jar, which was then filledthree-quarters full with sensitizer solution. The jar was then agitatedby turning the jar end-to-end for about 10 minutes. The beads were thenagitated by stirring by hand for about 10 minutes and rinsed thoroughlywith water. The beads were then transferred to a quart jar filledthree-quarters full with silver coating solution. To the quart jar, 24milliliters of reducer solution was added and the jar was capped andturned end-to-end for approximately 5 minutes. The solution was thenpoured through a screen to strain the beads and the beads were washed 3to 5 times thoroughly with de-ionized water. This electroless silverplating process was repeated three more times to produce a four-layersilver coating on the alginate beads.

Three grams of coated microencapsulated heat delivery vehicles wereanalyzed for their ability to generate heat after being immersed in thewetting solution of Example 12 and held at 50° C. The beads were testedat intervals of 4 hours, 8 hours, 24 hours, and 48 hours. The resultsare shown in FIG. 8.

As shown in FIG. 8, while the electroless silver plating process doesproduce a microencapsulated heat delivery vehicle including a moistureprotective layer, the plating process greatly diminishes the heatgenerating ability of the alginate beads.

EXAMPLE 14

In this Example, samples of pan coated alginate microencapsulated heatdelivery vehicles having three different coating thicknesses wereproduced and analyzed for particle strength. Specifically, the sampleswere analyzed to determine the rupture point or the point at which therupture force is strong enough to rupture the particles.

Four samples of P7-A pan coated alginate microencapsulated heat deliveryvehicle were produced by using the method of Example 12. Two samples ofP7-B pan coated alginate microencapsulated heat delivery vehicle wereproduced using the same method as used to produce the P7-A samples withthe exception that 1.5 times the amount of coating was used to coat themicroencapsulated heat delivery vehicle. Three samples of P7-C pancoated alginate microencapsulated heat delivery vehicle were producedusing the same method as used to produce the P7-A samples with theexception that 2.5 times the amount of coating was used to coat themicroencapsulated heat delivery vehicle.

To test particle strength, a TA Texture Analyzer (Software Version 1.22)(available from Texture Technologies Corporation, Scarsdale, N.Y.) wasused. Specifically, a single particle of each sample was independentlyplaced on a polycarbonate plate and force measurements were made using aone-quarter inch to one inch diameter flat probe, moving at a rate ofabout 0.25 millimeter/second to about 5.0 millimeters/second. As theforce load was applied by the probe, the particle deformed until itcracked or collapsed. Generally, the deformation of the particlecontinues until the applied force increases exponentially, indicatingthat the shell of the particle has been ruptured. As used herein, the“rupture point” is defined as the height of the first peak on the graphsin FIGS. 9-11, indicating a decrease in resistance caused by the outershell breaking. The results of the measurements are shown in Table 3 andFIGS. 9-11.

TABLE 3 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P7-A 1284 2 283 3 71 4 264 P7-B 1 228 2 151 P7-C 1 526 2 297 3 323

As shown in Table 3 and FIGS. 9-11, more force was required to crushsamples of P7-C than samples of P7-A or P7-B. Additionally, as shown inFIGS. 9-11, samples of P7-C did not appear to deform as much as samplesof P7-A or P7-B, as indicated by the steeper slope of the force curve.

EXAMPLE 15

In this Example, samples of alginate coated microencapsulated heatdelivery vehicle were produced and analyzed for particle strength.Specifically, the samples were analyzed to determine the rupture pointor the point at which the rupture force is strong enough to rupture theparticles.

Six samples of P7-F alginate coated microencapsulated heat deliveryvehicle were produced using the method of Example 12. Seven samples ofP7-G alginate coated microencapsulated heat delivery vehicle wereproduced using the same method as for making the samples of P7-F withthe exception that the samples of P7-G were soaked in the wettingsolution of Example 12 for 48 hours at a temperature of 50° C. Foursamples of P7-J alginate coated microencapsulated heat delivery vehiclewere produced using the method of Example 8. The P7-J samples were thencoated with Saran F310 using the method of Example 12 above.

To test particle strength, a TA Texture Analyzer (available from TextureTechnologies, Scarsdale, N.Y.) was used as described above. The resultsof the measurements are shown in Table 4 and FIGS. 12-14.

TABLE 4 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P7-F 1212 2 64 3 190 4 113 5 44 6 145 P7-G 1 163 2 49 3 76 4 260 5 44 6 32P7-J 1 88 2 233 3 84 4 49

As shown in Table 4 and FIGS. 12-14, more force was required to crushsamples of P7-F than samples of P7-G or P7-J. Additionally, as shown inFIG. 13, after the outer shell of the P7-G samples ruptured, thecompression force drops to almost zero, which suggests that the P7-Gparticles are hollow and offer no resistance after the outer shell isruptured. These results are compared to the P7-F samples, which were notsoaked in wetting solution. Once the outer shell ruptured, thecompression force drops on the P7-F samples, but plateaus above zero.This resistance after the outer shell of the P7-F samples rupture isattributed to the resistance of the anhydrous magnesium chloride oilmixture being forced out of the shell.

EXAMPLE 16

In this Example, samples of alginate coated microencapsulated heatdelivery vehicle comprising either silica or chitosan were produced andanalyzed for particle strength. Specifically, the samples were analyzedto determine the rupture point or the point at which the rupture forceis strong enough to rupture the particles.

Three samples of P6-C alginate coated microencapsulated heat deliveryvehicle were produced using the method of Example 12. Five samples ofP6-D alginate coated microencapsulated heat delivery vehicle wereproduced using the same method as for making the samples of P6-C withthe exception that the samples of P6-D were additionally coated with a0.5% (by weight) aqueous solution of chitosan prior to drying the beadsto provide improved particle strength. The samples of P6-D were thenrinsed and allowed to air-dry. Three samples of P6-E alginate coatedmicroencapsulated heat delivery vehicle were produced using the samemethod as for making the samples of P6-C with the exception that thesamples of P6-E were additionally coated with fumed silica after dryingthe beads to provide improved particle strength. The samples of P6-Ewere coated with 5% (by weight) Cabot M5 silica and allowed to air-dryand then jar rolled for approximately 2 hours.

To test particle strength, a TA Texture Analyzer (available from TextureTechnologies, Scarsdale, N.Y.) was used as described above. The resultsof the measurements are shown in Table 5 and FIGS. 15-17.

TABLE 5 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P6-C 138 2 31 3 56 P6-D 1 164 2 84 3 123 4 74 5 59 P6-E 1 71 2 54 3 72

As shown in Table 5 and FIGS. 15-17, more force was required to crushsamples of P6-D and P6-E than samples of P6-C. As such, it appears thatby adding the additional chitosan or silica protective layers theparticle strengths of the samples are increased.

EXAMPLE 17

In this Example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

To produce the microencapsulated heat delivery vehicle, calcium chloride(about 20 micrometers in particle size) was introduced into mineral oilto form a 25% (by weight) calcium chloride/75% (by weight) mineral oilcomposition that was mixed together thoroughly and had a resultingviscosity (25° C.) of about 300 centipoise. This composition wasintroduced dropwise from a separatory funnel into two liters of a sodiumalginate solution (1% by weight in de-ionized water, 300 centipoise at25° C.) and allowed to dwell in the solution for about 30 minutes undersufficient stirring to keep the drops formed upon addition into thesodium alginate solution separate. Most drops of the composition addedwere between about 4 millimeters in diameter and about 6 millimeters indiameter. After 30 minutes dwell time the formed microencapsulated beadswere removed from the sodium alginate solution and rinsed three timeswith de-ionized water and cast to air-dry at room temperature overnight.Stable microencapsulated heat delivery vehicles were formed having adiameter of about 4 to about 6 millimeters.

Once the microencapsulated heat delivery vehicles were formed, themicroencapsulated heat delivery vehicles were surrounded by a moistureprotective layer. To produce the moisture protective layer forsurrounding the microencapsulated heat delivery vehicles, themicroencapsulated heat delivery vehicles were placed onto a Tefloncoated pan and individually coated with a 30% (by weight) Saran F-310 inmethyl ethyl ketone (MEK) solution using a pipette. The MEK was allowedto evaporate leaving the saran film as a moisture protective layersurrounding the microencapsulated heat delivery vehicles to formsubstantially fluid impervious microencapsulated heat delivery vehicles.

A polyvinyl alcohol solution was then used to produce a fugitive layerto surround the substantially fluid impervious microencapsulated heatdelivery vehicles. To produce the fugitive layer, a 20% (by weight)solution of polyvinyl alcohol was prepared by hand stirring 20 grams of87-89% hydrolyzed polyvinyl alcohol (available from Sigma-Aldrich Co.,St. Louis, Mo.) into 80 grams of de-ionized water having a temperatureof 70° C. The polyvinyl alcohol solution was then applied using apipette to the substantially fluid impervious microencapsulated heatdelivery vehicles. Two coats of the polyvinyl solution were applied tothe substantially fluid impervious microencapsulated heat deliveryvehicles. The substantially fluid impervious microencapsulated heatdelivery vehicles coated with the polyvinyl alcohol solution were thendried in an oven at a temperature of 50° C. for 1 hour to produce themicroencapsulated heat delivery vehicles including the fugitive layer.

EXAMPLE 18

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A Ticacel® HV solution was thenused to produce a fugitive layer to surround the substantially fluidimpervious microencapsulated heat delivery vehicles. To produce thefugitive layer, a 1% (by weight) solution of Ticacel® HV was prepared byhand stirring 1 gram of Ticacel® HV powder (commercially available fromTIC Gum, Belcamp, Md.) into 99 grams of de-ionized water at roomtemperature. The Ticacel® HV solution was then applied using a pipetteto the substantially fluid impervious microencapsulated heat deliveryvehicles. Two coats of the Ticacel® HV solution were applied to thesubstantially fluid impervious microencapsulated heat delivery vehicles.The substantially fluid impervious microencapsulated heat deliveryvehicles coated with the Ticacel® HV solution were then dried in an ovenat a temperature of 50° C. for 1 hour to produce the microencapsulatedheat delivery vehicles including the fugitive layer.

EXAMPLE 19

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A gum solution was then used toproduce a fugitive layer to surround the substantially fluid imperviousmicroencapsulated heat delivery vehicles. To produce the fugitive layer,a 10% (by weight) solution of Gum Arabic FT was prepared by handstirring 10 grams of Gum Arabic FT (commercially available from TIC Gum,Belcamp, Md.) into 90 grams of de-ionized water at room temperature. TheGum Arabic FT solution was then applied using a pipette to thesubstantially fluid impervious microencapsulated heat delivery vehicles.To half of the substantially fluid impervious microencapsulated heatdelivery vehicles, two coats of the Gum Arabic FT solution were applied.To the other half of the substantially fluid imperviousmicroencapsulated heat delivery vehicles, four coats of the Gum ArabicFT solution were applied. The substantially fluid imperviousmicroencapsulated heat delivery vehicles coated with the Gum Arabic FTsolution were then dried in an oven at a temperature of 50° C. for 1hour to produce the microencapsulated heat delivery vehicles includingthe fugitive layer.

EXAMPLE 20

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A starch solution was then used toproduce a fugitive layer to surround the substantially fluid imperviousmicroencapsulated heat delivery vehicles. To produce the fugitive layer,a 30% (by weight) solution of PURE-COTE® B-792 starch was prepared byhand stirring 30 grams of PURE-COTE® B-792 starch (commerciallyavailable from Grain Processing Corporation, Muscatine, Iowa,) into 70grams of de-ionized water having a temperature of 70° C. The B-792starch solution was then applied using a pipette to the substantiallyfluid impervious microencapsulated heat delivery vehicles. Two coats ofthe B-792 starch solution were applied to the substantially fluidimpervious microencapsulated heat delivery vehicles. The substantiallyfluid impervious microencapsulated heat delivery vehicles coated withthe B-792 starch solution were then dried in an oven at a temperature of50° C. for 1 hour to produce the microencapsulated heat deliveryvehicles including the fugitive layer.

EXAMPLE 21

In this Example, the Gum Arabic FT fugitive shell made in Example 19 isremoved from the substantially fluid impervious microencapsulated heatdelivery vehicle.

To remove the fugitive shell, the substantially fluid imperviousmicroencapsulated heat delivery vehicles including the fugitive shellwere immersed in room temperature de-ionized water for 30 minutes. Thefugitive shell appeared to dissolve in the water and the substantiallyfluid impervious microencapsulated heat delivery vehicle became visiblysofter.

EXAMPLE 22

In this Example, a self-warming wet wipe including microencapsulatedheat delivery vehicles was produced according to the present disclosure.The temperature increase in the wet wipe upon activation of the contentsof the microencapsulated heat delivery vehicles was then analyzed.

To produce the self-warming wet wipe, two layers of a coform basesheet,each made of 30% (by weight) polypropylene fibers and 70% (by weight)wood pulp fibers and having a basis weight of 30 grams per square meter,were heat sealed together on three sides to form a pouch (2″×2″).Microencapsulated heat delivery vehicles were made by first producingthe microencapsulated heat delivery vehicles in accordance with a methoddescribed above and then 2.24 grams of the microencapsulated heatdelivery vehicles were placed inside the pouch and the fourth side ofthe pouch was heat sealed to form a wipe.

To produce the microencapsulated heat delivery vehicles, anhydrousmagnesium chloride (about 20 micrometers in diameter) was introducedinto mineral oil to form a 25% (by weight) magnesium chloride/75% (byweight) mineral oil composition that was mixed together thoroughly andhad a resulting viscosity (25° C.) of about 300 centipoise. Thiscomposition was introduced dropwise from a separatory funnel into twoliters of a sodium alginate solution (1% by weight in de-ionized water,300 centipoise at 25° C.) and allowed to dwell in the solution for about30 minutes under sufficient stirring to keep the drops formed uponaddition into the sodium alginate solution separate. Most drops of thecomposition added were about 3 millimeters in diameter. After 30 minutesdwell time the formed microencapsulated beads were removed from thesodium alginate solution and rinsed three times with de-ionized waterand cast to air-dry at room temperature overnight. Stablemicroencapsulated heat delivery vehicles were formed having a diameterof about 3 millimeters.

The wipe containing the microencapsulated heat delivery vehicles wasthen wetted with 0.7 grams wetting solution using a spray bottle. Thewetting solution comprised the following components: about 98.18% (byweight) water; about 0.6% (by weight) potassium laureth phosphate; about0.30% (by weight) glycerin; about 0.30% (by weight) polysorbate 20;about 0.20% (by weight) tetrasodium EDTA; about 0.20% (by weight) DMDMhydrantoin; about 0.15% (by weight) methylparaben; about 0.07% (byweight) malic acid; about 0.001% (by weight) aloe barbadensis; and about0.001% (by weight) tocopheryl acetate.

Once the wet wipe was produced, the temperature of the wet wipe wasmeasured by folding the wipe in half and inserting a Type K thermocouple(available from VWR International, West Chester, Pa.) into the center ofthe folded wipe. The wipe was then introduced into a standardpolyethylene bag, which was then laid onto six layers of paper toweling(commercially available as Scott Brand, Kimberly-Clark Worldwide, Inc.,Neenah, Wis.). The temperature of the wipe was measured to be 29.9° C.

The microencapsulated heat delivery vehicles were then broken using aCoorstek 60314 pestle (available from CoorsTek, Golden, Colo.). Thebroken shells of the microencapsulated heat delivery vehicles remainedinside of the wipe. As the microencapsulated heat delivery vehicles werecrushed and their contents exposed to the wetting solution, the wet wipebegan warming. The warming of the wet wipe was analyzed by using adigital thermometer (available from VWR International, West Chester,Pa.), which recorded at a 3 second interval. The temperature wasrecorded for 90 seconds, starting from the time the microencapsulatedheat delivery vehicles were crushed. The temperature of the wet wipeincreased to a temperature of 41.2° C.

EXAMPLE 23

In this Example, samples of pan coated alginate microencapsulated heatdelivery vehicles having fugitive shell layers made from variousmaterials were produced and analyzed for particle strength. Controlsamples of pan coated alginate microencapsulated heat delivery vehicleswithout fugitive shell layers were also produced and analyzed forparticle strength.

Nine control samples of 49-1 pan coated alginate microencapsulated heatdelivery vehicle without fugitive shell layers were produced using themethod of Example 12. Nine samples of 49-2 pan coated alginatemicroencapsulated heat delivery vehicle having a fugitive shell layermade from Ticacel® HV (commercially available from TIC Gum, Belcamp,Md.) were produced using the method of Example 18. Six samples of 49-4pan coated alginate microencapsulated heat delivery vehicle having afugitive shell layer made from PURE-COTE® B-792 starch (commerciallyavailable from Grain Processing Corporation, Muscatine, Iowa) wereproduced using the method of Example 20. Nine samples of 49-5 pan coatedalginate microencapsulated heat delivery vehicle having a fugitive shelllayer made from polyvinyl alcohol (commercially available fromSigma-Aldrich Co., St. Louis, Mo.) were produced using the method ofExample 17. Seven samples of 49-3 pan coated alginate microencapsulatedheat delivery vehicle having a fugitive shell layer made from Gum ArabicFT (commercially available from TIC Gum, Belcamp, Md.) were producedusing the method of Example 19. Eight samples of 49-6 pan coatedalginate microencapsulated heat delivery vehicle having a fugitive shelllayer made from Gum Arabic FT were produced using the same method asused to produce the 49-3 samples except that four coats of Gum Arabic FTwere applied. Five samples of 49-7 pan coated alginate microencapsulatedheat delivery vehicle having a fugitive shell layer made from Gum ArabicFT were produced using the same method as used to produce the 49-3samples and then the Gum Arabic FT was removed using the method as setforth in Example 21.

To test particle strength, a TA Texture Analyzer (Software Version 1.22)(available from Texture Technologies Corporation, Scarsdale, N.Y.) wasused. Specifically, a single particle of each sample was independentlyplaced on a polycarbonate plate and force measurements were made using aone-quarter inch to one inch diameter flat probe, moving at a rate ofabout 0.25 millimeter/second to about 5.0 millimeters/second. As theforce load was applied by the probe, the particle deformed until itcracked or collapsed. Generally, the deformation of the particlecontinues until the applied force increases exponentially, indicatingthat the shell of the particle has been ruptured. The results of themeasurements were averaged for each type of sample and are shown inTable 6 and FIGS. 18-24.

TABLE 6 Pan Coated Alginate Averaged Force (grams) MicroencapsulatedHeat required to rupture sample Delivery Vehicle Sample particle 49-11123 49-2 1274 49-3 707 49-4 1197 49-5 1131 49-6 849 49-7 Not Detectable

As shown in Table 6 and FIGS. 18-24, on average, more force was requiredto crush samples of 49-2, 49-4, and 49-5 than samples of 49-1.Specifically, the samples of 49-2, which have a fugitive shell layermade of Ticacel® HV Powder, required the greatest force to rupture,indicating that Ticacel® HV Powder provides the greatest protectionamong the materials in the Example against rupturing. The samples of49-4 and 49-5, which have fugitive shell layers made of starch andpolyvinyl alcohol, respectively, also provide improved protectionagainst rupturing. The samples having fugitive shell layers made of GumArabic FT were more easily ruptured.

Additionally, as shown in FIGS. 18-24, samples of 49-2, 49-4, and 49-5did not appear to deform as much as samples of 49-1, 49-3, and 49-6, asindicated by the steeper slope of the force curves.

With reference now to FIGS. 25-27, one embodiment of a dispensing systemfor dispensing warm wet wipes is indicated generally at 101. Thedispensing system 101 comprises a wet wipe container 103 (broadly, afirst container) having an internal compartment 105 in which one or morewet wipes 107 are disposed. Although discussed primarily herein incombination with warming utilizing heating agents (neat ormicroencapsulated), it will be recognized by one skilled in the artbased on the disclosure herein that the dispensing systems describedherein may also dispense cool wipes or wipes that can cool upon use.These cooling wipes may include a cooling agent as described herein inplace of the heating agent. Similar to the heating agents, the coolingagents may be added to the wipe or lotion as described herein in neat ormicroencapsulated form. When utilized, it is generally desirable for thecooling agent to reduce the temperature of the wipe surface by at leastabout 5° C., more desirably at least about 10° C., and still moredesirably at least about 15° C. As such, the term “temperature changeagent” may be used herein to generally refer to heating agents andcooling agents.

As used herein, the term “wet wipe container” is intended to refer to acontainer 103 in which the wet wipes 107 are disposed directly withinthe internal compartment 105 of the container or a container in which adiscrete package (not shown) of wet wipes may be removably disposed,i.e., wherein the wet wipes remain in their package within the internalcompartment of the container to permit replacement of the package of wetwipes without having to replace the container. In a particularlysuitable embodiment the wet wipes 107 disposed in the internalcompartment of the container may be any of the wet wipes describedpreviously herein as comprising an aqueous solution. Where multiple wetwipes 107 are disposed in the wet wipe container 103, the wet wipes mayalready be separated from each other, such as in a stackedconfiguration, or the wet wipes may be connected to each other in acontinuous web of wet wipes in a roll configuration as illustrated inFIG. 26 with sequentially adjacent wet wipes delineated by suitableperforations to allow the wet wipes to be separated upon dispensing fromthe wet wipe container.

In the illustrated embodiment, the wet wipe container 103 is generallycylindrical in shape in accordance with the roll of wet wipes 107contained therein. However, it understood that the wet wipe containermay be shaped other than cylindrical, such as rectangular or othersuitable shape, without departing from the scope of this invention. Aclosure, indicated generally at 109, for the wet wipe container 103 ishingedly connected thereto (e.g., by an integrally molded hinge or aseparate, suitable hinge mechanism) for hinged movement relative to thewet wipe container. In particular, the closure 109 is moveable betweenan open position (FIG. 26) in which the internal compartment 105 of thewet wipe container 103 is accessible, for example to load a roll of wetwipes 107 into or remove the roll of wet wipes from the container, and aclosed position (FIG. 25) in which the wet wipes are substantiallyenclosed within the internal compartment of the container. A suitablesecurement mechanism (not shown) releasably secures the closure 109 inits closed position. However, it is contemplated that such a securementmechanism may be omitted without departing from the scope of thisinvention. For example, a suitable biasing mechanism (not shown) maybias the closure 109 toward its closed position without departing fromthe scope of this invention.

In one particularly suitable embodiment the closure 109 comprises alotion container 111 (broadly, a second or auxiliary container) havingan internal compartment 113 that is separate from the internalcompartment 105 of the wet wipe container 103. Lotion is disposed withinthe internal compartment 113 of the lotion container 111 such thatlotion in the lotion container is out of contact (i.e., free fromcontact) with the wet wipes 107 in the wet wipe container 103. As usedherein with respect to the lotion contained in the lotion container 111,the term “lotion” is intended to include materials that are liquid orsemi-liquid (i.e., gels, soft solids, creams, roll-on liquids) at roomtemperature; that is, materials that tend to flow at room temperature.In one particularly suitable embodiment, the lotion comprises at leastin part a heating agent capable of generating heat upon contact with theaqueous solution of the wet wipe 107. In another particularly suitableembodiment, the lotion comprises at least in part the microencapsulatedheat delivery vehicles described previously as comprising a heatingagent capable of generating heat upon contact with the aqueous solutionof the wet wipe 107. The exact chemical makeup of the lotion is notnarrowly critical, although it is generally desirable to have anon-aqueous lotion to reduce the risk of premature heat loss. The lotionmay include various components, such as for example, mineral oil,petrolatum, silicones, polyethylene glycol, polyols, ethoxylatedglycols, esters, glycerin, fatty alcohols, waxes, plant oils, animaloils, hydrogenated hydrocarbons solubilizers, moisturizers, cleaningagents and/or the like. Additionally, the lotion may contain viscositymodifying agents including both thickeners and thinners to produce alotion with the desired flow characteristics and may contain suspendingagents to ensure that the temperature change agent is evenly distributedthroughout the lotion container. It is this lotion that includes themicroencapsulated heat delivery vehicles that then may be dispensed ontothe wet wipe 107 to facilitate the heating thereof. Although generallyless preferred, the microencapsulated heat delivery vehicles includingthe heating agent can be loaded into the lotion container 111 anddispensed neat onto the wet wipe 107. In such an embodiment, themicroencapsulated heat delivery vehicles act as the lotion.

It will be recognized by one skilled in the art based on the disclosureherein that in some of the embodiments described herein where the lotionincluding the heating agent is held separately from the wipe, andtherefore separately from the aqueous solution held on the wipe, untiljust prior to use, that the heating agent, such as, for example,anhydrous magnesium chloride or anhydrous calcium chloride, could beintroduced neat into the lotion; that is, the heating agent could beintroduced directly into the lotion without first beingmicroencapsulated. Because the lotions are generally non-aqueous based,the heating agent can survive over time in the lotions without losingpotency as there is not available water for the heating agent to reactwith. Once dispensed onto the wipe including the aqueous wet wipesolution, the heating agents held in the lotion in this embodiment canreact with the water to produce heat without any need for rupturing of amicrocapsule shell. In one suitable example of this embodiment,anhydrous magnesium chloride can be introduced directly into mineral oiland the combination thereof utilized as a lotion for dispensing onto awipe.

Generally, a sufficient amount of heating agent, such as anhydrousmagnesium chloride (whether added directly to the lotion withoutmicroencapsulation or added to the lotion in microencapsulated form asdescribed herein), is added to the lotion such that upon the dispensingof the desired amount of lotion onto a conventional sized wipe (about7.0 inches by about 7.7 inches), the wipe will contain from about 0.1grams of heating agent to about 0.5 grams of heating agent, desirablyfrom about 0.3 grams of heating agent to about 0.4 grams of heatingagent. This amount of heating agent will typically produce an increasein temperature on the surface of the wipe of about 15° C. It will berecognized by one skilled in the art that the exact amount of heatingagent and exact amount of lotion to be added onto a wipe may varydepending upon the exact size of the wipe, and the desired temperatureincrease.

An applicator, indicated generally at 121, is held in assembly with thelotion container 111 in communication with the internal compartment 113of the lotion container. The applicator 121 is suitably operable toapply lotion from the lotion container 111 to a wet wipe 107 while thewet wipe is disposed at least in part within the internal compartment113 of the wet wipe container 103, and more suitably as the wet wipe isbeing removed from the wet wipe container. For example, in theillustrated embodiment the applicator 121 comprises a roller 123disposed within an elongate opening 125 formed in an open end (e.g.,opposite the hinged end) of the lotion container 111. In particular, thelotion container 111 is generally configured at the elongate opening 125to sealingly seat the roller 123 in the opening so that a portion of theroller surface is disposed within the internal compartment of the lotioncontainer, in contact with the lotion in the container, and a remainingportion 127 of the roller surface is disposed exterior of the lotioncontainer.

The applicator roller 123 is suitably journaled in the lotion container111 to permit generally free rotation of the roller relative to thelotion container. Upon rotation of the roller 123, lotion in the lotioncontainer 111 coats the surface of the portion of the roller within theinternal compartment 113 and the coated portion is rotated exterior ofthe roller for transferring the lotion from the coated portion of theroller onto a wet wipe 107. It is contemplated that the applicator 121may comprise other than the roller 123 arrangement illustrated in FIGS.25-27, such as a pump mechanism (not shown) or other suitable deliverydevice that is operable to deliver lotion from the internal compartment113 of the lotion container 111 onto a wet wipe 107 within the wet wipecontainer or more suitably as a wet wipe is being removed from the wetwipe container.

In one particularly suitable embodiment where the lotion comprises amicroencapsulated heat delivery vehicle including a heating agentcapable of generating heat upon contact with aqueous solution, thedispensing system 101 further comprises an activating device, indicatedgenerally at 131, that facilitates rupturing of the microencapsulatedheat delivery vehicles as a wet wipe 107 (having the lotion appliedthereto) is removed from the wet wipe container 103 to permit contactbetween the heating agent and the aqueous solution of the wet wipe tothereby provide a warm wet wipe. In the illustrated embodiment, theactivating device 131 comprises a roller 133 (broadly, a bearingsurface) mounted on the wet wipe container 103 in opposed, closelyspaced relationship with the applicator roller 123 to define a nip 135therebetween in the closed position of the closure 109 (e.g., the lotioncontainer 111). The nip 135 defines an opening through which individualwet wipes 107 are drawn sequentially from the wet wipe container 123.The activator roller 133 is suitably journaled in the wet wipe container103 for substantially free rotation relative to the wet wipe container.

The spacing between the rollers 123, 133 (i.e., the size of the nip) issuitably in the range of about 0.1 mm to about 10 mm, and more suitablyin the range of about 0.5 mm to about 1.5 mm so as to apply a rupturingforce to the microcapsules, and more particularly to squeeze or compressthe microcapsules with sufficient force to rupture the microcapsules. Inanother embodiment, the rupturing force is suitably in the range ofabout 0.001 to about 250 pounds per linear inch (pli), and more suitablyin the range of about 0.01 to about 25 pounds per linear inch (pli).

The rollers 123, 133 may have an outer surface constructed of anysuitable material including, without limitation, metal, ceramic, hardplastic, rubber (such as, for example rubber of greater than 60durometer) or other suitable polymer. The rollers 123, 133 may each havean outer surface made from the same material, or they may be made fromdifferent materials and remain within the scope of this invention.

It is also contemplated that the outer surfaces of the rollers 123, 133may be smooth as in the illustrated embodiment. In other embodiments theouter surface of one or both of the rollers 123, 133 may be textured(not shown) to further facilitate the rupturing of the microcapsulesand/or to facilitate lotion distribution and transfer. For example, theouter surfaces of one or both of the rollers 123, 133 may be engravedwith a series of small cells or grooves such as in the manner of agravure roll, knurled, dimpled or otherwise suitably textured.

It is understood that the activator device may comprise a bearingsurface other than the roller 133 illustrated in FIGS. 25-27 to apply arupturing force to the microencapsulated heat delivery vehicles andremain within the scope of this invention. For example, a suitablebearing surface may comprise a flat or arcuate surface (not shown) inplace of the activating device roller 133, i.e., in opposed relationshipwith the applicator roller to form a compression nip with the applicatorroller. A suitable rupturing force may alternatively be applied to themicroencapsulated heat delivery vehicles without passing the wet wipe107 through a compression nip 135, such as by pulling the wet wipe tautover the bearing surface at an angle relative to the dispensingdirection in which the wet wipe exits the wet wipe container 103, withthe bearing surface thus acting as a fulcrum at which a force is appliedby the bearing surface generally normal to the wipe. It is furthercontemplated that the rupturing force may instead comprise a non-contactforce, such as that generated by ultrasound, heating or other suitablenon-contact generated forces.

In operation to dispense a warm wet wipe 107, starting with the closure109 of the dispensing system 101 secured in its closed position, a wetwipe is manually grasped and pulled outward from the wet wipe containerthrough the nip 125 formed between the applicator roller 123 and theactivating device roller 133. As the wet wipe 107 is drawn through thenip 135, the friction between the wet wipe and the applicator roller123, and between the wet wipe and the activating device roller 133,causes the rollers to rotate respectively relative to the lotioncontainer and the wet wipe container. Rotation of the applicator roller123 operates to apply lotion from the lotion container 111 onto the wetwipe 107 as the wet wipe enters the nip. A rupturing force is thenapplied to the microencapsulated heat delivery vehicles containing theheating agent, e.g., by the rupturing force (e.g., the compression orsqueezing force) applied by the rollers 123, 133 at the nip 135therebetween, to rupture the delivery vehicles.

The heating agent is released from the ruptured delivery vehicles andcontacts the aqueous solution in the wet wipe 107 to cause a reactionwhich warms the wet wipe. The wet wipe 107 is suitably pulled outwardfrom the wet wipe container 103 to a length at which perforationsdilineating the wet wipe from the sequentially next wet wipe are locatedoutward of the nip 135. The wet wipe 107 is then pulled in a directiontransverse to the dispensing direction of the wet wipe, i.e., pulledalong the perforations, to separate the warmed wet wipe from thecontinuous roll of wet wipes remaining in the wet wipe container 103.

While the activating device 131 of the embodiment of FIGS. 25-27 isuseful in applying a rupturing force to the microencapsulated heatdelivery vehicles applied to the wet wipe 107, it is contemplated thatthe activating device may instead be omitted so that as the wet wipe ispulled from the wet wipe container the applicator 121 applies the lotionto the wet wipe and the wet wipe is then removed from the wet wipecontainer. The microencapsulated heat delivery vehicles can then beruptured after the wet wipe 107 has been removed from the wet wipecontainer 103 to provide a warm wet wipe.

FIG. 28 illustrates an alternative embodiment of a dispensing system,generally indicated at 201, similar to the dispensing system 101 exceptthat the closure 209 of this alternative embodiment comprises a simpleclosure panel 210 hinged to the wet wipe container 203 and having anelongate housing 212 at its free end (i.e., opposite its hinged end).That is, no lotion container 111 and applicator 121 are present in sucha dispensing system 201. Rather, wet wipes 207 disposed in the internalcompartment 205 of the wet wipe container 203 already have themicroencapsulated heat delivery vehicles including a heating agent asdescribed previously incorporated therein. An activating device 231 forthe embodiment of FIG. 27 comprises a pair of rollers 233, 237, onemounted in the housing 212 of the closure panel 210 and the othermounted on the wet wipe container 203, in opposed, closely spacedrelationship with each other to define a nip 235 therebetween. Each ofthe rollers 233, 237 is suitably journaled for generally free rotation.The spacing between the rollers 233, 237 and the rupturing force appliedby the rollers is suitably as described previously.

To dispense a warm wet wipe 207, starting with the closure 209 (e.g.,the closure panel 210) of the dispensing system 201 secured in itsclosed position, a wet wipe is manually grasped and pulled outward fromthe wet wipe container 203 through the nip 235 of the activating device231. While passing through the nip 235, a rupturing force is applied bythe rollers 233, 237 to the microencapsulated heat delivery vehiclescontaining the heating agent, e.g., by compression, to rupture thedelivery vehicles. The heating agent is thus released and contacts theaqueous solution in the wet wipe 207 to cause a reaction which warms thewet wipe. The wet wipe 207 is suitably pulled outward from the wet wipecontainer 203 to a length at which the perforations dilineating the wetwipe from the sequentially next wet wipe are located outward of the nip235. The wet wipe 207 is then pulled transverse to the dispensingdirection of the wet wipe, i.e., along the perforations, to separate thewarmed wet wipe from the continuous roll of wet wipes remaining in thewet wipe container 203.

It is understood that the activating device 231 of the embodiment ofFIG. 27 may comprise a single roller (broadly, a bearing surface), andthe single roller may be opposed by a stationary member (not shown) suchas a flat or arcuate surface to define a nip therebetween. In otherembodiments, both rollers 233, 237 may be omitted and a suitable bearingsurface may comprise a flat or arcuate surface (not shown) over whichthe wet wipe 207 is pulled taut at an angle relative to the dispensingdirection in which the wet wipe exits the wet wipe container 203, withthe bearing surface thus acting as a fulcrum at which a force is appliedgenerally normal to the wipe. It is further contemplated that theactivating device 231 may instead apply a rupturing force that is anon-contact force, such as that generated by ultrasound, heating orother suitable non-contact generated forces.

When introducing elements of the present disclosure or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions withoutdeparting from the scope of the disclosure, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

1. A dispensing system for dispensing a wet wipe, the dispensing systemcomprising: a container; a wet wipe disposed in the container, the wetwipe comprising an aqueous solution and microencapsulated deliveryvehicles including a temperature change agent, the temperature changeagent being capable of changing the temperature of the wipe upon contactwith the aqueous solution, the container being configured to permitremoval of the at least one wet wipe therefrom; and an activating deviceconfigured to contact the wet wipe as the wet wipe is dispensed from thedispensing system, the activating device comprising a bearing surfaceand a roller in opposed, spaced relationship with the bearing surface todefine a nip therebetween to facilitate rupturing of themicroencapsulated delivery vehicles as the wet wipe is removed from thecontainer, the spacing between the bearing surface and the roller beingin the range of from about 0.1 mm to about 10 mm to apply a rupturingforce to the microencapsulated delivery vehicles of the wet wipe in therange of from about 0.001 to about 250 pounds per linear inch, wherebythe rupturing of the microencapsulated delivery vehicles allows forcontact between the temperature change agent and the aqueous solution ofthe wet wipe to thereby dispense a wet wipe.
 2. The dispensing systemset forth in claim 1 wherein the activating device is removablyconnected to the container.
 3. The dispensing system set forth in claim1 wherein the bearing surface is formed integrally with the container.4. The dispensing system set forth in claim 1 wherein the bearingsurface is a roller.
 5. The dispensing system set forth in claim 1wherein the microencapsulated delivery vehicles comprise a corecomposition surrounded by an encapsulation layer, the core compositioncomprising a matrix material and a heating agent, and wherein themicroencapsulated heat delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.
 6. The dispensing system setforth in claim 5 wherein the matrix material is selected from the groupconsisting of mineral oil, isopropyl myristate, silicones, copolymerssuch as block copolymers, waxes, butters, exotic oils, dimethicone,thermoionic gels, plant oils, animal oils, and combinations thereof. 7.The dispensing system set forth in claim 5 wherein the heating agent isselected from the group consisting of calcium chloride, magnesiumchloride, zeolites, aluminum chloride, calcium sulfate, magnesiumsulfate, sodium carbonate, sodium sulfate, sodium acetate, metals,slaked lime, quick lime, glycols, and combinations thereof.
 8. Thedispensing system set forth in claim 1 wherein the micronencapsulateddelivery vehicles comprise a substantially fluid-imperviousmicroencapsulated delivery vehicle comprising a core composition, anencapsulation layer surrounding the core composition, and a moistureprotective layer surrounding the encapsulation layer, wherein the corecomposition comprises a matrix material and a heating agent, and whereinthe microencapsulated delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.
 9. The dispensing system setforth in claim 1 wherein the microencapsulated delivery vehiclescomprise a stabilized substantially fluid-impervious microencapsulateddelivery vehicle comprising a core composition, an encapsulation layersurrounding the core composition, a moisture protective layersurrounding the encapsulation layer, and a fugitive layer surroundingthe moisture protective layer, wherein the core composition comprises amatrix material and a heating agent, and wherein the microencapsulateddelivery vehicle has a diameter of from about 5 micrometers to about5000 micrometers.
 10. The dispensing system set forth in claim 1 whereinthe temperature change agent is a cooling agent.
 11. A dispensing systemfor dispensing a wet wipe, the dispensing system comprising: a wet wipecontainer having an internal compartment for containing wet wipes; a wetwipe disposed in the internal compartment of the wet wipe container, thewet wipe comprising an aqueous solution; a lotion container having aninternal compartment, separate from the internal compartment of the wetwipe container, for containing a lotion, a lotion contained within theinternal compartment of the lotion container free from contact with thewet wipe in the wet wipe container, the lotion comprisingmicroencapsulated delivery vehicles including a temperature change agentcapable of changing the temperature of the wet wipe upon contact withaqueous solution; an applicator in communication with the internalcompartment of the lotion container and operable to apply the lotion tothe wet wipe while the wet wipe is disposed at least in part within thewet wipe container; and an activating device configured to contact thewet wipe as the wet wipe is dispensed from the dispensing system, theactivating device comprising a bearing surface and an applicator rollerin opposed, spaced relationship with the bearing surface to define a niptherebetween to facilitate rupturing of the microencapsulated deliveryvehicles as the wet wipe is removed from the container, the spacingbetween the bearing surface and the applicator roller being in the rangeof from about 0.1 mm to about 10 mm to apply a rupturing force to themicroencapsulated delivery vehicles in the lotion on the wet wipe in therange of from about 0.001 to about 250 pounds per linear inch, wherebyrupturing of the microencapsulated delivery vehicles permits contactbetween the temperature change agent and the aqueous solution of the wetwipe to thereby dispense a wet wipe.
 12. The dispensing system set forthin claim 11 wherein the applicator is operable to apply the lotion tothe wet wipe as the wet wipe passes through the nip.
 13. The dispensingsystem set forth in claim 11 wherein the bearing surface is a roller.14. The dispensing system set forth in claim 11 wherein the lotioncontainer is connected to the wet wipe container.
 15. The dispensingsystem set forth in claim 14 wherein the lotion container is moveablerelative to the wet wipe container to facilitate loading of the at leastone wet wipe in the internal compartment of the wet wipe container. 16.The dispensing system as set forth in claim 11 wherein themicroencapsulated delivery vehicles comprise a core compositionsurrounded by an encapsulation layer, the core composition comprising amatrix material and a heating agent, and wherein the microencapsulateddelivery vehicles have a diameter of from about 5 micrometers to about5000 micrometers.
 17. The dispensing system as set forth in claim 16wherein the matrix material is selected from the group consisting ofmineral oil, isopropyl myristate, silicones, copolymers such as blockcopolymers, waxes, butters, exotic oils, dimethicone, thermoionic gels,plant oils, animal oils, and combinations thereof.
 18. The dispensingsystem as set forth in claim 16 wherein the heating agent is selectedfrom the group consisting of calcium chloride, magnesium chloride,zeolites, aluminum chloride, calcium sulfate, magnesium sulfate, sodiumcarbonate, sodium sulfate, sodium acetate, metals, slaked lime, quicklime, glycols, and combinations thereof.
 19. The dispensing system asset forth in claim 11 wherein the micronencapsulated delivery vehiclescomprise a substantially fluid-impervious microencapsulated deliveryvehicle comprising a core composition, an encapsulation layersurrounding the core composition, and a moisture protective layersurrounding the encapsulation layer, wherein the core compositioncomprises a matrix material and a heating agent, and wherein themicroencapsulated delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.
 20. The dispensing system as setforth in claim 11 wherein the microencapsulated delivery vehiclescomprise a stabilized substantially fluid-impervious microencapsulateddelivery vehicle comprising a core composition, an encapsulation layersurrounding the core composition, a moisture protective layersurrounding the encapsulation layer, and a fugitive layer surroundingthe moisture protective layer, wherein the core composition comprises amatrix material and a heating agent, and wherein the microencapsulateddelivery vehicle has a diameter of from about 5 micrometers to about5000 micrometers.
 21. The dispensing system as set forth in claim 11wherein the temperature change agent is a cooling agent.
 22. A processfor producing a wet wipe capable of providing a temperature change, theprocess comprising: providing a wet wipe in a container, the wet wipecomprising an aqueous solution and microencapsulated delivery vehiclesincluding a temperature change agent, and the container comprising anactivating device configured to contact the wet wipe as the wet wipe isdispensed from the dispensing system, the activating device comprising abearing surface and a roller in opposed, spaced relationship with thebearing surface to define a nip therebetween to facilitate rupturing ofthe microencapsulated delivery vehicles as the wipe is removed from thecontainer, the spacing between the bearing surface and the roller beingin the range of from about 0.1 mm to about 10 mm to apply a rupturingforce to the microencapsulated delivery vehicles of the wet wipe in therange of from about 0.001 to about 250 pounds per linear inch; drawing awet wipe out of the wet wipe container; and rupturing themicronencapsulated delivery vehicles as the wet wipe is drawn from thewet wipe container to allow the temperature change agent to contact theaqueous solution and provide a temperature change on the wet wipe.